We love the GFV one bedroom villas, very luxurious. We haven't stayed in the studios there because we don't do studios with only one queen bed. Polynesian is only studios (unless you have a boatload of points and can book the bungalows). You are arriving and departing before the marathon, so you should be able to find something to book at seven months out. Both are going to be hard to book (have you checked the RAT to see what is available at this point).
I just checked the RAT and there is only partial availability for the GFV studio, but the one bedroom is open. Polynesian is open for the standard studio, but not the lake view studio.
You can watch the fireworks from Narcoossee if you dine there (it's really nice). If you stay at the GF, you can walk over to the Polynesian or dine at 'Ohana. It takes about 5-10 minutes to walk between the two resorts (we were just at the GFV and ate dinner one night at 'Ohana).