I also live in MN, and traveled to MSK for surgery, and I also have an HAI pump, so I traveled monthly for that while I was having that treatment.
I had never been to NYC prior to going to MSK, and I was not comfortable staying far from the hospital or clinic. There are a lot of posters who are from the New York area who I am sure could give you some pointers if you are more adventurous than I! I stayed at the courtyard Marriott midtown east hotel, as another poster said. Very convenient to the outpatient clinic. It actually is quite convenient for when you are hospitalized, if your caregiver will be staying in a hotel. There is a free shuttle between the outpatient center and the hospital. They are about 2 miles apart, though, so it is walkable. As for the hotel, they offer a special rate for MSK patients. Be sure to speak to the local manager of the hotel; reservations will often tell you there is not a patient rate, but there is. When I had surgery, I had my liver, colon and ovaries resected, as well as had the HAI pump placed. I was in the hospital a week, and my surgeons asked I stay in NYC for a week after being released, to make certain I was stable before flying home.
We are not wealthy people either. I will say I was, and continue to be, amazed by everyone who has helped us along the way. Sometimes it is very hard to accept the help, but let them. There is such a strong sense of community in the Midwest, partuicularly MN. It makes people feel good to help out - just be prepared to say thank you, A LOT, and write a lot of thank you notes!
Good luck to you, if you have any questions, feel free to ask or PM...
Colleen
Edited to add: when I travel, I fly delta. They have a medical fare, which I believe saves you 10% on the airfare. The biggest benefit is that if you have to change your ticket, for unexpected medical reasons, they waive the change fee. Which is $100 per person per direction. I had to change several times, so that made a big difference! You have to call the airline to get this fare, and they will need your doctors information and information about your condition.