You can attend college anywhere. Online courses are helpful when you can do your work on your time (not all allow you to do that) and work around weekend training and such. Most schools will work with you on your military obligation, it might even be one of your questions to them before enrolling. MANY soldiers attend college because of the 'free' money you get for it, it doesnt hurt to ask around for ones they are using that are military friendly. There is a post in here somewhere that people listed military friendly schools if i remember correctly. If not and you arent for sure set on that school you mentioned in NYC, start a post and they will let you know!
Understand, though, that the National Guard may not pay 100% for every school you want to attend. Not all schools are created equal! Before you commit to paying tuition at an institution, double check with your state benefits to verify how much you're covered for. Here's some general information on how Federal Tuition Assistance works: TA And information on the GI Bill: GI Bill