First of all, we should find out who wants and is able to come.

Exactly. As soon as we decide on the organizers, they will immediately organize a poll.

And for that, it is necessary to announce the exact dates and the program of the event.

Perhaps qualifiers won't even be necessary.

If you set too global a goal, you'll fail. I remember there was a very strong general desire to hold a "Tournament of the Century" on the League of Heroes, but it was inflated so excessively that they couldn't finish it. Therefore, the tournament needs segmentation. If one segment falls through, it won't affect the other segments.
A large tournament will initially consist of, say, 5-6 small ones, independent of each other. Due to the disjointed and fragmented nature of the Heroes community, maximum freedom is needed for these mini-tournaments.
For example, St. Petersburg holds a tournament on TE (calling it a city championship), playing only on weekends. Moscow also plays on weekends, but on SoD.
Michurinsk — on SoD, over three days. Minsk, St. Petersburg, and Kiev propose their own schedules, whatever is most convenient for the participants.

Of course, without the recognized Heroes centers: Moscow, St. Petersburg, Minsk, or Ukraine — the tournament loses significant value.

The dates should be reasonable. It seems to me that two timeframes are convenient — September (it's still almost summer, no need to deal with fur coats) and January (half the month is non-working). That is, where they will play for a long time, on weekends — it's better to start earlier; where it's fast — it doesn't matter, whatever is more convenient for the organizer.

The final — somewhere in May of next year in the worst case; if everyone works promptly — then perhaps right during the January holidays.

Organizers don't need to jump out of their skins — they just run a regular tournament and take care of the guests' accommodation, if there are any.

Although this is all secondary - first we need to collect a list of those interested, then split them by cities for the qualifiers. And only then choose the time and place of the gathering.

First — identify the organizers in the major Heroes centers and the core of the local scene. Using Michurinsk as an example. I'll contact Mizrael, Scorp, and Stas from Tambov, then the Old Osskol people who have been with me — Mystik and Dmitry, and I'll add Stiki to them. From the local scene, I'll wait for the weekend arrival of Veland and Pavel, add Cannabis, Lekha, Lavren, and Flesh to them — even having 8-9 people from this list in the tournament would already ensure a quite decent champ, even without other guests. Either way, I'll be ready to host the tournament.

Other organizers will do roughly the same. Minsk, Moscow, St. Petersburg — they have a slightly different specificity due to the size of the cities and the number of players.

Going to look at the map to see where this town is...

I'll explain using Michurinsk as an example. It's a major railway hub, 400 km south of Moscow; almost all trains from the capital heading south go through us. And there are plenty of trains from east to west (and vice versa). There are two stations, so the guests' bad habit of not informing in advance which station they are arriving at sometimes irritates both them and me.
Let's say, the trip from Moscow to us (400 km) costs 550 rubles. Round trip, accordingly, 1100 rubles.

Hotel accommodation has become more expensive — 800 rubles per day. Let's calculate: they arrive Friday evening, that's one day; Saturday is the second; on Sunday we check out and leave things at my place or locked up in the club. Total 2 days = 1600 rubles.
10-12 rubles — 1 hour of play in the club; playing at least 10-12 hours a day (yes, just like that) — that's 100-150 rubles per day, approximately 400 rubles for the tournament. Total mandatory costs — 3000-3200 rubles.
Next — food; you can bring a cow with you, or you can have lunch in quite decent cafeterias with home-cooked food, a normal lunch for a hundred, we'll add about 900 rubles for three days.

Total all costs — 4000 rubles. The only additional cost — by agreement, a tournament entry fee, say 1000 rubles, so that the winner feels good going home not only in a moral but also a material sense. Again, if there are financial difficulties, the organizers can be understanding — the player plays without an entry fee, but if they take 1st place, they won't receive the prize fund (it will go to the player who took the highest place among those who paid the fee).

In total — for 4 or 5 thousand rubles, a person gets the opportunity to spend three days socializing in the Heroes circle, show themselves, and most importantly, observe others. Perhaps doubts about the level of play will vanish on their own.
I think it will be most expensive for guests to travel to Yekaterinburg; I looked at the map, checked the scale, and felt dizzy. But they have great traditions of holding tournaments and a strong scene. Minsk — I don't think it will be much more expensive than Michurinsk. I don't know about Kiev. Moscow and St. Petersburg — well, if there's a way to make it cheap in those cities — it should be used. But overall, these scenes would be ashamed not to hold their own tournaments, because they have always been leaders in Heroes.

THE MAIN THING is to FORM AN ORGANIZING COMMITTEE of people ready to conduct their regional tournaments at a decent level. So far there are two — Yekaterinburg and Michurinsk, we're waiting for more. It would be good if Vika from St. Petersburg...

Afterwards — we will agree on the conditions and dates for the mini-tournaments, and discuss potential sponsors.
After that — the cores of the tournaments are formed from local players, and guests are invited.

I recall someone inviting people to a tournament in Zelenograd.

Perhaps not. Only proven centers and people — and there will still be enough problems.
Some simply won't calculate their strength in organizing and recruiting participants, some are just people of one day — they wake up in the morning and no longer want to hold a tournament. One must approach holding a large event with a margin of safety; qualifiers only where it is guaranteed they can take place.