That's about 130 pounds, at least seven "20 pound" exchange bottles. That's a lot of LPG. It all depends on how cold it gets, how much you use the furnace, which is the highest rate user of the fuel in a RV (unless you bake a lot).
My experience, traveling in temperatures running 40-60 F daytime, 20-40 F at night, is that I have to top off my ~40 pound tank every 3-4 days. In those conditions, I don't run the furnace at all during the day, but it runs at night when stationary.
Your LPG capacity is a lot larger, your usage potentially higher depending on conditions. You could use more than 130 pounds of LPG on a two-week trip into New England at this time of year, depending on how cold it is, and how warm you want to be. You are not likely to run into freezing conditions, which would require you to burn fuel to make heat to protect the RV, so it is a matter of comfort level. That, and the what the weather is.
I've never found it to be a problem, traveling, because I use commercial RV parks (my late wife liked KOAs). In winter or marginally winter conditions, I tracked the level of LPG stored in my tanks, and when it dropped below half, I refilled. With 40 pounds, the interval could be 2-3 days, or 2-3 weeks. But I never had problems finding a place to refill, because I was choosing RV parks that provided LPG refill service. My practice has been to refill at 1/3 to 1/2 of the tank capacity.
There is no way to predict LPG usage for you, on 2 week trip. It could be almost nothing, it could be a lot, depending on the weather you encounter and how warm you need to be. If you used a lot of LPG enroute, you could likely refill when you arrive at your destination, and if need be, fill again before starting your return trip.
