There's an opinion that the restriction on the availability of fire magic after the second day can be bypassed. The day counter on the map (as well as many other counters in the game) is represented by a 16-bit number. Therefore, after the 32767th day, the counter goes into "negative," after which events, for example, those tied to specific "dates," stop triggering - until the 65536th day (which is also the 1st day) arrives. I think that this will also work with quests that depend on deadlines, although it needs to be checked, of course.))
I tested this idea experimentally. Indeed, after 1171-1-7 (32767th day), you can pass any passage guardian limited by a non-negative deadline, i.e., less than 32768 days. In the attached save, the guardian allows passage up to day 112, but on 1171-2-1, it can be passed. Thus, all such timings, except for direct failure for a specific deadline/direct victory for the companion, become irrelevant)
Yes, this trick also allows you to create guardians limited by a condition not only "no later" but also "no earlier" - if only someone in their right mind would come up with a map for 1170+ months)