How long is too long to travel In a fifth wheel.

Two years ago we traveled up through Alberta, British Columbia, The Yukon, and Alaska with a 40' 5er and 3500 Dually. And while some places were tight we made it.
Last summer we did all the Atlantic Provinces, including Ferries to and from Newfoundland with the same TV and a 43' 5er.
Now we're headed up into Manitoba to Thompson to go on a Polar Bear sightseeing adventure.