As this is not a connection, my standard advice is to allow at least 2-3x the MCT as a rule of thumb. For a connection, there are simple ground logistics. For a transfer between tickets, the issue includes everything from weather to mechanical to immigration issues on the inbound. If OP is a no show for his AC ticket, it will be cancelled and will retain whatever value if may under its fare rules. Likely $0.

Travel insurance rarely covers no shows across separate tickets. Check your policy carefully.

As noted above, it may well be just as well to change to the nonstop to YYZ. If not, I would book a room at BOS and take the first flight up the next morning.