Let's just run down the two best all-Interstate options you have. BTW, I used Groton as your starting point.
1) Shortest: I-95 to Rye NY, I-287 around NYC, I-80 through PA and OH where it merges with I-90, and I-90 the rest of the way. You can, of course use options like staying on I-80 just past Chicago and then I-39 north to rejoin I-90. That route is roughly 2,960 mi. (city center to city center).
2) glc's route: As listed I-84/I-81/I-80/I-76/I-71/I-70/I-74/I-80/I-29/I-90 (with bypasses). That comes in at 3,100 mi., but saves a lot on tolls, certainly more than you'd spend on gas for the extra 150 mi. or so, and while CT-9 from Groton to Hartford is technically not an Interstate, it is of Interstate quality.
If you're starting from New Haven (DLA) or Waterbury (ACE) you'll have to make slight adjustments to your initial route, but the object is to get around NYC as easily as possible and then onto I-80 ASAP. The basics of the main portion would still be the same. Given a choice, I'd probably go with glc's route which is only a bit longer and does avoid some major cities and the attendant tolls.
Oh, and BTW, there are very nice
'rest areas' all along whatever route you choose.
AZBuck