Trying to be proactive and need some guidance from UA experts. I’ve got a flight via EWR tomorrow afternoon (ex-YYZ) but it looks like the weather is going to be pretty bad up the US east coast and my onward domestic flight to TPA may get missed and rerouting would be difficult that late in the day. I see space available on flights via ORD to TPA. My plan is to do a Same Day Change after midnight, calling in to move from a EWR connection to an ORD one. Should I still check in for my EWR flight this afternoon or hold off until I get confirmed on the new flights via ORD? Used an RPU so might lose my upgrades, though ExpertFlyer shows F still open on both flights so UA appears to be holding back on confirming CPUs.