I'm thinking of taking a trip to Zion National Park (4 nights) sometime late September or October. I've been looking at the hotels and there seems to be a mix of hotels already booked up around that time and open rooms. We're hoping to spend under $200 a night for a room. Do we need to book a room ASAP or do we have time to continue looking and planning? Although I'm pretty sure I want to do Zion National Park, I'm also considering a couple of other places, but if hotel rooms book up quickly during September and October I don't want my tendency towards indecision to get in my way.