Bad timing. Send encouragement pls!

I've tried potty training my son (2.5) multiple times - every time has been terrible and a fight. We told him that after our Disney World trip next week we're saying bye bye diapers for good. We'll, today he decides that he's doing it on his terms and he took off his diaper and told me he "wears underwear now please". Someone send me some encouragement or stories about potty training around a big trip...I have no idea if this will last more than this evening but I'm freaking out a bit hahaha