Yes, it is hit or miss. Checking the list is really step 1.
I wasted time looking into importing a made-in-Canada Bigfoot Class C only to find it wasn't on the list of vehicles you could import to Canada
For new or newer units, Both Winnebago and Airstream show 2017's on the list. PW shows 2015's. Roadtrek only up to 2012.
The list changes so it really is the only source.