Freezer shelf life of feeders

I have often read about ensuring frozen feeders should not be any older than 1 month old, even in a deep freeze and not the top section of a regular fridge freezer. Nutrient value goes down etc. How valid is this? A new pet store opened in our small town and for the first 6 months, we could get frozen feeders from him, we still can by pre-ordering. The store owner has very recently brought in live adult feeder mice which is great. My BP will now take either live or F/T with few refusals but he does prefer live. It is illegal to own live rats in Alberta and this makes frozen rats harder to find and more expensive.

I hate driving in the city of Edmonton. If this store goes under like the last one did, how long can frozen feeders last in an upright dedicated freezer? I want to reduce driving trips but I don't want to jeopardize Monty's health.

I used to breed mice but that was a B movie horror show. Have your only snake go on a hunger strike and you don't know anybody who needs feeders, live or frozen....

From what I've been told up to a year, as long as the bag is sealed up good. Also don't think there is any difference in which freezer they are stored in.

If sealed properly, six to nine months easily.

I've stored feeders as long as 10 months but it's usually more like 6 months.