I'd love to see the rest of the mysterious fortress around the resurrection celebration aka Easter bunny holiday IF not earlier, then another half a year for part 2. Or around mid october 2022 a year after the first part of the duergar fortress was opened up to players. Part 3 yet to come after that? Part 4? Hahha!
But it would make some sense, 2nd being a bit more wilderness and the tower. 3rd Baldurs gate, dungeons, miniature planes, many buildings and towers and more.
Then there are DLC.. which work beautifully in the format of say a adamantium dollhouse with a mordenkainens mansion, version bigger, dimensionally squeezed inside it. Or a island of Crabpeople (those are friendly) the pirates however are not, and the caves with a lost kuotoan city has pirate treasures, mutants and worse.
Even a grand quest into the lower planes, lorokans tower may hold a gateway...
All in all, no need to expand the map as such, the dlc areas can work on separate maps.