We did a trip to Canada 2 years ago. We made a few mistakes along the way but we stayed at a number of different sites.
We flew in to Vancouver, picked up a car and drove up to Whistler for 3 nights, and managed to see brown bears on our first guided trip out. We then drove on to Vancouver Island, and by far the best stop on the whole trip was at Painters Lodge in Campbell River, where we had another few nights. Here we had Bald Eagles nesting in the trees and saw them all daily. Harbour seals out by the jetty, and saw Whales, Orca, dolphin while out on boat trips, visited an Island that was full of various sea birds, and then went to where 2 rivers met and were amazed to see 20-30 (if not more) Eagles perched on the rocks waiting for the Salmon run to start.
We could have spent a whole week here, it was fantastic. We then drove over to the Pacific Rim, and stayed in Tofino for another few nights before coming home. More whales, more Eagles, plus we saw a few iconic perching birds (American Robin, Chicadee, Blue Jay etc).
As mentioned above, it's a VERY big place, driving from Vancouver to the East coast will take you a whole week, and people think nothing of a 300 mile round trip to see people. Unless you go there you will never get a sense of the size, and we only scratched a part of the surface. It is by far the best holiday we have ever had, and the ease with which you can be on your own, and hear nothing but nature has to be experienced.
People are very nice, food was excellent (I never thought I'd ever get fed up of eating salmon!) and the craft beers are good to. We did a fly drive, if we did it again we would spend less time in the cities, and opt for an SUV rather than a basic car, as when you go from place to place you cover lots of miles.