I had to wait 6 days (including the weekend) for my biometrics appointment. There may be more than one office that does them in your area. It doesn't have to be done at an actual USCIS office, and you get to choose which location you go to. There are Application Support Centres around and there might be one in your area. That's what I went to. When you have submitted your application online, you'll be able to see what locations are available and which dates/times each of those have for scheduling your biometrics.
You can start your application now and save what you've finished, but it's only saved for 7 days. So, if you want to keep it current, you'll obviously have to log in before that period is up every week to keep renewing the same application (and application number).
Is there any way you can get the necessary docs together any sooner? If so, you could do the application now or asap, schedule the best biometrics appointment, and then send everything away within the allowed 2 weeks. That way you'd have more time to play with rather than waiting and hoping to get your visa back in time to have a Nov. 28th departure.