Each year they seem to tinker a little bit with which restaurants are open during the party, and some (TS and CS) are always closed. LTT is a safe bet, as is (usually) Tony's, but CP might not be open past 6. Either make an early ADR (prior to 6) to get your pick of places, or consider LTT (assuming you don't want CS, which will probably be limited to 2 places as nother poster has mentioned). We did LTT last year at 5:30 and it worked out well in terms of timing for the party. We weren't wild about the food and won't go back, but it was definitely worth trying once.