Not daft Dominatio. Personal choice, but I'd never fly over extensive fog out of gliding distance of clear air because as you say, you might need to force-land (engine failure being the most obvious possibility).
Some pilots will bet their lives on the collection of nuts, bolts, castings, bearings, pipes, mags etc that comprise a running aero engine. I'm not one of them, and it's why a not insignificant part of the PPL syllabus is dedicated to forced landings without power.