My guess is that they're deformed/damaged by now after ice crystalized
in the lens.  Just a guess though.  Every tried freezing cream cheese?
Small ice crystals literally form out of the moisture, and it can't be
thawed back into its original consistency.

OTOH - I also suppose it depends on how cold.  I seem to recall from
basic HS chemistry that salts bring down the freezing temp in a
non-linear way.  It might not have frozen.

+20 F weather shouldn't hurt the CLs. Saline solution is usually liquid at
this temperature. +10F is getting a bit chilly and you might possibly have
some defects. I live in the land of -20 F and worse during winter. The only
problems tend to occur when someone lets the packs freeze solid at -30F and
then try to boil the packs to thaw them out while still out in the tundra.
We tell mushers and trappers to keep the lens packs and solutions in pockets
in the middle or inner layers of clothing.

Our winter time inbound shipments get chilled down to +10F quite often with
no problem. The mail outs from here can sometimes go to places that actually
get cold (-50F or worse) and we have no idea how long they sit outside going
from village to village. We haven't heard too many issues, however.

Treat them like a frostbit toe and gently warm them back. They should be
fine considering the mild temperatures they were exposed to.

Carl