The Australian PM recently made an error in which he referred to Canada as “Canadia”. He quickly corrected himself, just one of those errors that can occur in speech, I suppose.
Most of the places that end in -a but not -ia have demonyms formed by the addition of an -n.
Some exceptions among national demonyms:
Burmese*, Guyanese, Chinese, Maltese
Panamanian (This is interesting in that Panama is the most similar named nation to Canada in terms of stress placement).
Among the US states, we could also add Floridian, Carolinian, Alabamian. Of these, Florida has similar stress placement to Canada.
So what do you think is behind it? Did someone decide Canadian sounded better than Canadan? Is there some other historical reason?
*Burman has previously sometimes been used as a general demonym for Burma and is still used to denote a particular ethnic group = Bamar)