Are Familiars affected by weather conditions? [closed]

Since a familiar is a magical spirit (celestial/fey/fiend, albeit in a physical form), does it have any restrictions to travel in cold/hot areas for scouting purposes, or altitude of mountain air? I’m trying to use my owl familiar to scout mountains, and my DM tells me that it’s too cold and/or high for him to be able to scout. Would I have to recast and change the species of the owl to snowy, or would being a celestial owl prevent having to do this? Obviously if its too hot they burn and die, and if it gets too cold they freeze, but as a magical spirit that can travel between dimensions, where should the line be drawn? The 3e/3.5e template is way overpowered (spell resistance, etc), but this feels almost entirely too weak. How limited is a familiar by their physical form if they’re no longer considered a "beast?"