Freezer info

[flatheed]

I have 2 freezers in my garage. one cheap one and one good one, both used for fishing purposes. during the recent cold spell one (the good un) defrosted. the cheap one didnt, obviously some kind of thermostat issue as the weather has warmed up its working again. has anyone any knowledge of some method of avoiding this happening? can you adjust the thermo? bypass it? taking it inside aint an option although i had thought of getting another crap one, but if theres some way of sorting it?

any info appreciated cheers in advance.