Lada withdrew from the Canadian market in 1997, due to increased competition from Korean automakers, and a completely outdated product base. Now things are different. Lada actually makes kinda modern cars, for the most part, and the Koreans have moved upmarket, leaving a gap for budget brands. I think someone like Lada could move right into that market.
One of the ways that this could be successful is if they kept their model range small and simple, four models at most. You could have the Kalina hatch and Granta (sedan version of the Kalina), the X-Ray subcompact CUV;
And for the shits and giggles, the Niva.
Another former eastern bloc carmaker that could make good inroads is Dacia, who, like Lada, have sold cars in Canada before. Unlike Lada though, they sold about 3 cars and nobody remembers that they actually sold cars here. Which is a good thing, no bad reputation to shake off, unlike Lada.