If you arrive 4 days before an event I would imagine you'll have no problem registering. I know they are capping entries this year but you should be fine to register a couple of days before the event.
Suggest you go to a bank and buy dollar travellers cheques and change them up when you get there. That's what I do - just need a pocket with a strong zip!!
I'm going out on the 10th for 10 days will play a couple of the smaller events but looks good value at Caesars for their deep stack festival and the Venetian deepstack must be quite soft as apparently Compo won one last year!!

All the best for your trip.