Have the battery and charging system receive a clean bill of health. Have no doubts about this. Maybe also get a fresh oil change with 5w/30 oil. Change it out back to your usual sooner than normal after you get back to NYC.

Carry extra washer fluid.
Cans of fix-a-flat.
Thin rubber gloves in case you need to poke around the car in inclement weather.
Spare light bulbs for the low beams, front and rear turn signals, and stop lights. Deicer fluid to squirt on the washer nozzles.
Extra long snow brush to clear your roof and hood in one or two quick sweeps.
And an extra ice scraper in case the first breaks.
Driving gloves. I use disposable cotton gloves; just don't get them wet.
Music, your favorite for driving long stretches.
Hand lotion, lip balm.
Rags.

Goggles. You don't want to accidentally get squirted with hot fluid in the eyes in case you have to pop the hood and poke around. (Ask me how I know...)

*** I'm glad you asked. Exactly 1 year ago, I stopped for gas, and the attendant (this is NJ) pointed out dripping red fluid on the ground. I decided to drive to a mechanic instead of to Washington DC as I had been about to, but the coolant light went on. I pulled over immediately at a gas station. I checked under the hood and the overflow bottle was fine and full. I pressed on a hose clamp and got squirted with coolant on my left ear and temple, the fact that I wear glasses saved me from getting coolant in the eyes. The top radiator neck was cracked with the hose and clamp intact! (Plastic radiator, 1997 s90, your v70 may have the same set up.) I washed up in the mens room, and called AAA for a tow to the same mechanic. And our story continues...

I was about to go meet a woman over New Years. When I called to let her know what happened, she told me she rear ended someone that stopped too short and had to get her SUV repaired, and would not have been able to meet me anyway with the hassle of needing it taken to a body shop et al. I eventually met up with her halfway between both our places, in Maryland, a month later, and I thought we hit it off. We could have continued talking for hours, but the Indian restaurant was closing at 3pm and we both had to drive back the same day. Over the phone we talked for a few weeks. But she never had the time to meet a second time. Our story then ended right there.

...So glad I did not get stuck somewhere on I-95 with a cracked radiator over New Years eve/day... lost my Priceline-paid but unused hotel room on the original aborted trip.

Oh, and by the way, on the road, never pass up a chance to pee. :-)