Don't expect Montreal to be inexpensive. After all, it's a top-tier city, and the savings that Americans have previously come to expect when visiting Canada -- effectively a 20% discount -- have vanished with the fall of the American dollar. OTOH, your hotel tax is effectively zero, because you can get it refunded (in USD, drawn on a US bank; no tricks, and I've done it myself before, so I know it works).

The key issue is that the people deciding where to hold Worldcons are the people who are least sensitive to price. People who are sensitive to price are unlikely to vote in a contested election because they perceive that they are potentially "throwing their money away" if the bid they prefer doesn't win. People like me, who vote every year, never make that sort of calculation.