Hi Anders,
I do have CodeWarrior 6.3 with S08 running on my Windows 10 64bit system, just tried it quickly with a simple project:

Some remarks:
- I'm using the CodeWarrior V6.3

- that IDE toolchain has been developed in the 64bit Windows XP era, back in 2008 (so more than 10 years ago), and does not support officially later Windows versions
- I have it installed on my machine (not sure anymore how I did it, but there is How-to Directly Install CodeWarrior 6.3 Classic in Windows 10 or 7 x64 (Unofficial Method) ).
- the problems for sure are any USB drivers. I'm using the P&E Multilink (the 'old'/legacy brownish debug interface boxes, and they work fine. Not sure if the later green and blue (universal ones) ones are working (would have to check if I have time).
- I do have the latest P&E drivers installed on my system (from the MCUXpresso IDE 11.0.0, see my article about it: New NXP MCUXpresso Eclipse IDE v11.0 | MCU on Eclipse )
- The IDE crashes on exit (when I quit the IDE). Annoying, but does not impact me.
- I have seen that USB licensing dongles will be an issue on Windows 10, so better don't get down that route. Try out the free code size limited version first to be sure things are working.
- I believe the biggest thing is the IDE itself: the build tools (compiler, linker, etc) work fine (and are 32bit applications) under 64bit.
- the debugger (HI-WAVE) is an external application and can be used standalone too
- I have used the toolchain and debugger from Eclipse too with using make files, see Make my Make with Eclipse and MCU10 | MCU on Eclipse . That would bypass the need for the IDE.
So it 'works' for my legacy S08 projects, but I'm not actively using it. I cannot comment on the S12 side as I currently do not maintain any of these projects. I still have a board around, but not sure if it will work.
I hope this helps,
Erich