There's a huge price increase in new england once you go buried propane. If you can even find a tank. The above ground tanks, though not as pretty, are much more affordable. Ours are actually free if we fill them 1.5 X their capacity in a year. Two 100 gallon tanks next to each other will likely get you through a good amount of time in your area. Maybe even 1.
Also, you've mentioned pulling permits, etc. Are you gc'ing this yourself? We just built, and i can assure you, not using a (GOOD) gc will add a fair amount of time and headaches. Part of my job is construction management in a way, and i still didnt want to tackle that! Plus, time was of the essence.
Be ready to order your cabinets, and what not as soon as you have a plan in place and your site work people are ready to go. Siding choice as well. Some things are really easy to get, but if you want something very particular, you may have to wait. This is also where using a GC will help you. They can steer you in the right direction to supply houses that can actually fulfill on time. We were just about 6 months to completion once the foundation was done. That was with crews there nearly every day. Our gc did a nice job keeping the subs as tightly scheduled as possible.
Solar panels may help, but Im not sure what your state's rules are. Are you netzero? Buying the panels is almost always the best option. At that rate, you might want to think about a power wall. Especially if you were ever to think about an automatic generator anyways... The price for the powerwall is more, but they're pretty wild.
My two cents at least!