For anyone facing this situation, the fix I found is as follows:
-> Run game
1 - Determine map region(s) containing your base (guide here). Note that you need to select the "Ch" tick box in the top F3 menu for the chunk submenu to display.
-> Exit game/launcher fully
2 - Get your seed name (see cloud's comment here for random gen)
3 - Back up/move game saves folder to new folder called BAK or to different location altogether
4 - Delete old game saves from default save location
5 - Delete generated worlds folder (or rename with a leading _ )
-> Run Game
6 - Generate a new world using your original seed name
-> Exit game/launcher fully
7 - Copy map region(s) for base(s) to game save -> Region folder
8 - In the Player folder, delete enclosed files and copy the contents from your old save Player folder to the new
-> Run Game
9 - Enjoy fresh map generation with you old player, gear, gamestage, base and even map markers. EVERY map region not saved/copied from your original save will be reset. Note that, if you have them, 'outpost' bases/loot save locations will need to be determined in step one.
Basic explanation, but it worked a charm for me. The only bug I've found so far is my furnaces now show 5000+ minutes of fuel with no fuel in them. Will likely destroy and remake them soon.
I'm following this thread, so don't hesitate to ask questions. Of course, you could go OG 7D2D status and start from scratch. However, this roll for me was a good one and I wanted to keep it going...