I am temporarily enjoying the experience of living in a *small* camper.
It has a small icebox (well, actually, a small refrigerator, but how
often does one get the chance to use the word 'Icebox' these days )

Thee are some two- or three-portion-sized frozen foods I covet (e.g.,
fish [pre-cooked, and not], salibury steak, mac and cheese, meatloaf)
but don't buy because I'm concerned about their safety if I don't eat
all the 'portions' right away. Can you give me some guidance, please,
about how long they might stay 'safe' in the icebox if parts of them
have or have not been heated; or portions of them heated and eaten
while the remaining portions remain in the frig (for how long?) ...
that kind of thing.

Christopher A. Steele