I can see where snow or ice accumulation might pose a problem on a box trailer, but on an Airstream?
Naw, like water on a duck's back. That is just one more reason 60% of them ever built are still in service, even in Alaska.
The rounded roof and corners are not just aerodynamic for towing, they allow snow and ice to slide off when the temp warms.
Somebody correct me if I'm wrong but I don't think aluminum and/or vulkem expands/contracts with changing temperatures.
But it was wise of you Janet to put the guests out there rather than yourself, just in case.