Ok ,just a few thoughts here ,they might be relevent to your situation or perhaps not .

Bikes are cheaper in the US , buy it and insure it there ,then travel to Canada .
BC insurance is expensive if you land here , the province [govt ] is the only place to get it ,so for western Canada ,buy the bike and insure it in Calgary where they have private companies doing insurance .

Second hand bikes are expensive at the dealers ,buy new and don't bugger about looking for bikes from private individuals as you will waste a lot of your vacation time .

If you want to do gravel and some off road ,get a KLR they have a big tank as standard and will do what you want and are cheap .A dr650 might be better [IMHO it is ] but in standard form they don't have a big tank etc .

Get a 650 road bike if you want to do tarmac long distance ,they are cheap enough and have the speed and comfort for long highway stints ,anything bigger is a waste of money .
Something like a 650 Strom will be easy to sell at the end of your trip ,or you could leave it at a dealer and sell on consignment .

Avoid Sportsters and cruisers , unless "the look" is important to you .They are a pain in the arse.

Bring over soft bike luggage or buy it here it's fairly cheap,it's all you'll need for a short duration trip .

Get an idea of bike prices from Blackfoot Motosports
[Not many people like dealing with them ,there are better bike shops in Calgary who will more than likey do a better deal for you ,but you'll get a good idea of what's available .]

Can't speak for the Eastern side of the country but I imagine the situation is about the same .

Good luck and have fun !

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