POUGs are only one class upgrades, and if I've read it correctly for the flight in question you are both WT.

That CW upgrade looks to me to be a fare difference upgrade, it's not a POUG which are clearly advertised as a special time limited offer - see the Dashboard for examples of what it looks like (and in any case would be for WTP). If you bought that revenue ticket via an OTA and many TAs then that will be the best you can expect in advance of getting to the airport, you would only have a small chance of a POUG at OLCI, not in advance, whereas at the airport you can both request an AUP to WTP or CW. YYZ - LHR prices are shown in the Dashboard thread on the topic, and LGW would be the same or a bit lower. It would almost certainly have been cheaper to buy CW in the first place, rather than the fare difference now.

For the Avios ticket, your better bet will be to change the redemption to WTP or CW with Avios (if I have understood that you are currently in WT). It may even be a rare example of where buying some Avios is cost effective. I don't see any availability on a dummy booking at the moment but it would not surprise me if it opened up right at the end of July or early August. There may be a case to move hotel / Amex miles into BAEC in anticipation of this, particularly if there are other uses of Avios open to you if this doesn't work out. Essentially AUPs on Avios only happens when they are fairly desperate to push people forward, POUGs are only for one class upgrades, so in fact you should be looking not at CW availability, but WT availability. If there was a POUG offer on the Avios ticket it would be entirely possible to be at a different price to the revenue ticket, entirely possible that one of you is offered it but not the other.

So I would do a brief daily check of both bookings about 2 am UK time or later (refreshing the App if that is how you are accessing MMB) but mainly look to do an AUP at the airport.