The modern equivalent to your old map is Eastern_Europe 1070_10939 and it's only 564MB so it'll fit
All you need to do is
backup your device first > delete your old map > extract new map to the XL > then activate it with
FastActivate (instructions are provided)
* Btw, don't leave multiple posts on the forum for the same subject...it's not our fault you left it to the last minute to start asking questions