Thanks for checking all that -- I appreciate it!
Sadly I have zero Avios in my account right now, so I can't buy them, and I don't have time to transfer them.
We are frankly just fine with WTP on such a short day flight; I can't justify spending £1000+ for the upgrade. A surprise upgrade would be nice, but it isn't really necessary.
Will set an alarm for 07:30 tomorrow and see how things look.