Porting a Sol-only campaign isn't that big of a deal, especially since I don't care about leader names getting changed. Just have to write down facilities, wealth and minerals, as well as shipyards and techs researched. It's pretty simple, just a lot of fiddling.
Re-creating a jump network is a massive pain in the butt because you have to do it via DB editing. At least you can now modify systems in-game so you get the planetary systems correct but yeah, as far as I know people with multi-system empires - empty systems changing doesn't affect your AAR after all - usually keep playing until the end before moving to the next version.