I suppose it depends on how long you're staying, too. if you're going to burn 1200L of fuel pulling a trailer round trip, but only staying for 1 or 2 nights, then yeah, it makes more sense to Air BNB it.
if, however, you're going to park the trailer for 2 weeks, then the trailer starts to make more sense. It depends where you go, too. Airbnb's and hotels in Banff can be expensive, but a campsite is the same price in Banff as it is anywhere else in the country.