The concern with freezing is that it's unlikely lyophilization from these vendors is truly moisture free - there's almost certainly some water content in the vials. Depending on just how much, it's mixture with the filler and peptides means it will freeze at a lower temperature. When the moisture freezes it has the potential to damage adjacent peptides. Couple that with most kitchen freezers having defrost cycles that will result in the peptides heating up a bit, and you might have lots of thaw/freeze cycles. This is why the -80C freezers are sought after - they're cold enough and stable enough that you shouldn't have to worry about this.
Personally, I bought one of those -40F freezers off amazon and stash the peptides between layers of gel blocks to increase the thermal mass and insulate them.