Most of the top recommendations are, unfortunately, probably going to be full on reservations. Especially at prime time slots.

Thames Street Oyster House does walk ins. The lobster roll is phenomenal. $150 seems very doable unless you go overboard with the raw bar and/or alcohol. Cinghiale has some availability. Bluebird has some availability and does walk ins at the bar. Jong Kak would be a good time.

If you're up for a bit of an adventure you could go to Zahav in Philly as they used to take walk ins promptly at 5pm. But you need to get there early as there will be a line. They're currently doing a $75 prix fixe menu and their food is absolutely awesome. The menu was bigger pre-COVID but it seems to still include many of the hits, particularly the pomegranate lamb shoulder.

I definitely suggest calling to verify NYE hours if you cannot score a reservation online.