I had bagels from St. Viateur while on a roadtrip in Montreal a few weeks ago... Since then, I've been jonesing for some Montreal bagels in TO. I've seen St. Urbain on my occasional trips to St. Lawrence, but never thought of grabbing anything there until I saw that they sold smoked salmon spread.
On my recent visit to the market, I had to buy the smoked salmon spread at under $6 and since it was end of day, I grabbed 2 half dozen bags of bagels (flax and sesame) on sale for $3 each. They weren't fresh out of the oven, but they were made that same day and it was pretty good when the bagel was toasted with a schmear of smoked salmon spread.
It's not quite like St. Viateur, but it's the closest I can get to in Toronto!