My old man has a bunch of .dox stuff saved. He has complicated large files saved that are not supported by any of the FOSS conversion tools. I’ve tried Libre office, Abi Word, and every command line tool and converter I can find. These are entire book sized files.
I have a W10 machine with Word. Is extracting the .exe and running it with wine feasible without making an epic mess or massive project of this?
No
You need Windows