Originally Posted by
guv1976
There will be some Canadian departure taxes on the flight from YUL to NYC. For 8,500 Chase UR points, you could fly to YUL, and take Amtrak back from YUL to NYP. (Chase UR points transfer to Amtrak Guest Rewards.) The only thing I'm not sure of is whether you can transfer just 4,500 UR points to BA, or whether you would have to transfer an even 5,000 points.
Some taxes yes. But you can still do the return trip for 9k avios and $58.
Depends on your personal money-to-time ratio.
The JFK/LGA-YUL usually have plenty of award space: looking at a random weekend in about four weeks I get availability for 7 flights (LGA/JFK together), first one around 7am, last one around 9pm for the outbound, and 6 options for the return, first one at 7am, last one at 7pm.
ETA: another advantage of flying is that you do US customs at YUL which (unlike YYZ) is a really quick and painless process, and you arrive at LGA/JFK as a domestic passener.