Toronto!!

I'm also NYC-based and go to Toronto a few times a year for work. When I can, I always try to stay the weekend because I love this city! Downtown TO is very walkable, there's a great international food scene (maybe a hot take, but I think it's better than NY), and I also really like the shopping. I basically just do the same stuff I would do with a solo weekend in NY lol, but I love it. Super short flight and exchange rate is favorable, so you don't feel pain when converting prices back to USD. Go any time but winter, which is just as painful as everyone says it is

The domestic flight version of this rec is Chicago