Let me suggest a few simple straight-line distances (
source) between significant cities (arbitrarily defined):
(W-E) Vancouver to Montreal: 3690 km
(W-E) Vancouver to Halifax: 4434 km
(N-S) Inuvik to Vancouver: 2202 km
(N-S) Iqaluit to Montreal: 2055 km
(SW-NE) Lisbon to Moscow: 3910 km
(N-S) Stockholm to Palermo: 2385 km
(N-S) Helsinki to Athens: 2471 km
So the east-west distance is similar. The north-south distances (I've left out uninhabited places in Canada's extreme north) are similar, but for Canada that includes large stretches or largely uninhabited land -- it is well-known that almost all of Canada's population lives in a small sliver of land close to the US border.
I think the misconceptions from European visitors regarding Canada's size have nothing to do with the size of the whole country, but rather have to do with a travel plan that looks a priori reasonable:
Quebec City - Montreal - Ottawa - Toronto - Niagara Falls
That's over 1000 kms with a lot of open space... Edmonton-Calgary-Rocky Mountains-Vancouver would be even worse... compared with some hypothetical road trip in Western or Central Europe where you can always manage to see something historically or culturally significant between large cities with a lower total distance.