Since the automatted reinstall with mhwd failed because of lack of internet connection, I tried to establish one (wireless, I have no cable handy) in the command line using nmtui (got the hint from this thread, which is, funnily enough, about my exact same problem - with older solution). I ran
sudo mhwd -a pci free 0300
once more. This time it worked perfectly, and I had the intel driver back (it chose i915)
Thanks so much everyone for taking the time to respond! It’s always the same, I need to post my problem before I can think of the right info to search the web for…
note:
Anything CLI-based would not have been necessary to launch in chroot (I think) bcs I had access to TTY2.