I don't know either, and I am also surprised if the NH company will let you take it out of state, but I have 2 suggestions:
1) Call the place you are renting it from and ask if they know.
2) Call the airline and ask for someone who deals with special needs. They should know. And then you might want to see if there is a number for the airline actually at your airport as a final check.
If they won't gate check it, they should be able to give you a manual chair to use.