Happened once to me prior to Covid. I was upgraded at the gate heading to ORD.

In early 2024 I had to wait 3 weeks for confirmation to MCO. I was very close to just paying for the upgrade as my wife and kids were already booked into Biz and I wanted to make sure I was sitting next to them.

Personally, in your circumstances I would ask if LAS or SFO were available and if so, I would cancel and rebook (assuming you bought a smart fare) to one of these and then take a short hop domestically.