Road/Gravel bike: flat pedals (Diety Deftrap).
Fat bike: flat pedals (Deity TMAC)
FS MTB: switch between TIME XC clipless and one of the above flat pedals.
Flat pedals in warm weather: Ride Concept Hellions
Flat pedals in colder or wet weather: gortex Teva hiking shoes.
Flat pedals in really cold weather: Columbia Bugaboots.
Clipless shoes: old pair of mavic XC MTB shoes, new pair od some Bontrager lace ups.