meals in nyc for shabbat
are there options that are prepaid for shabbat, friday night and/or shabbat lunch, that are in the vicinity of the st regis (which i think is 55th and madison)
Prime at the Bentley was doing that, and may still be. Chabad does it somewhere near the Public Library, perhaps billed as Chabad of Midtown. I understand that it is quite an upscale Chabad in a culinary sense, as is Prime, of course.
Chabad of Midtown is at 5th Ave/57th Street. They do very nice Shabbat meals, with good catered food. It's not a restaurant, but it's classic stuff like chicken soup and gefilte fish, all very fresh and tastes good, and is served nicely on china, etc. The crowd there tends to be diverse and interesting, with tourists, people traveling for business, students, etc. Unlike at a restaurant (in my experience), there is a friendly vibe where you feel comfortable chatting with random people at your table.