They eat more often.
A crocodile in Australia would eat once a month or less. If it moved to Norway it would probably do alright eating hot chicken soup 3 times a day.
Actually, crocodilians, and for that matter, most reptiles slow their metabolisms down and hibernate in cold weather.
They eat more frequently in warmer months, and live off of reserves in cooler weather. Crocodilians are very efficient at using energy, an adapation perhaps. that ensured their survival on Earth for eons.
Argonians are argonians, not reptiles, amphibians, or fish.
Who knows how they survive, perhaps they cast a fire spell for .000000001 on self at constant effect.
It's not like they actually exist .