Originally Posted by phlwookie
The difference in availability is probably because the YUL-PHL flight is sold out in several of the discount coach fare classes. This if YUL-PHL shows S0, then YUL-PHL-LGW will show S0 as well, as you wouldn't be able to get an S fare all the way from YUL to LGW on that routing, even though PHL-LGW has S seats.
I agree that PHL-LGW looks good, and it will also help that it's July 4th, so most people travelling for the holiday will already be at their destination and won't have left yet, and most in the US have Monday Jul 5th off.
I'll caution that since I live in PHL, I generally don't connect for transatlantic flights, but I would go ahead and ask in YUL. It can't hurt, though most of the upgrades in my experience will happen in PHL. Perhaps someone else in here can comment on success at confirming an upgrade before getting to PHL.
A dummy booking shows 20 of the 41 Envoy seats on US 98 assigned, though there are probably a few others with Envoy tickets who haven't yet grabbed seat.
Overall I'd say it looks pretty good for you right now, but the wildcard will of course be how many US preferred try to go for it as well. What kind of upgrade cert do you have?
I agree. Do keep in mind that if you ask for the upgrade at YUL and the PHL-LGW leg is confirmed in Envoy Class, once the upgrade coupon is collected, then you can ask to be put on the First Class upgrade list from YUL to PHL. I don't think US Airways will have that many Preferred customers flying this route. Also, sometimes there are last-minute cancelations, you might end up getting upgraded from YUL to PHL as well. Best of luck to you.