Well, XL is a bit too much, but not more than L + basement; we weren't talking about XL with a basement...
Map size L: 108x108
Map size XL: 144x144
If the map has a basement, multiply the result by 2 ;)
P.S. My calculator gave me
108x108x2=23328
144x144=20736
Added 2 minutes later
XL with a basement - no one is saying...
XL without a basement - they said it's too much
And L with a basement is bigger than XL without a basement - therefore, it's even more too much!