This sounds right. The current 100kwh S/X packs are still using the 18650 cells, and the 2170 cells are supposedly ~30% more efficient today. Give Tesla a few years and they will be able to find additional efficiencies. I think that double stacking 2170 cells will be doable. My guess is they will be stacked even higher below the rear seats (like a Bolt) just in front of the rear axle. I expect the rear seat of the new Roadster to be like that of a Porsche 911- pretty much useless. The expected range/pack size/efficiency is telling about the expected weight of the new Roadster too. I'm hoping that Tesla can match the Model S's drag coefficient (0.24), and they are predicting 620 miles of range out of 200kwh- indicating an expected efficiency of 323 wh/mi. A 100D today is rated for about 317 wh/mi. This indicates that either 1) the new Roadster is going to weigh 4500+ pounds or 2) it will be lighter, but with a higher Cd of drag. I'm hoping its the latter, as the car has a pretty serious rear diffuser and a small rear wing as well, both of which increase drag. The prototype was also wearing Michelin Pilot Sport Cup 2 325/30ZR21 rears and 295/35ZR20 fronts. This is a VERY sticky tire compound and even if Tesla pairs back that tire width for production, we're still looking at much more drag from the tire width (personally, with 7000+ lb/ft of torque, I want 325-section rears). Still, I have a hard believing that the car will be under 3800-3900 pounds, which means this will be more of a GT car than a featherweight sports car like the original 2800lb Roadster. Ballistically quick in a straight line, AWD, higher curb weight (plus more sound deadening that OG Roadster), likely higher center of gravity, and super long cruising range = GT car. This thing will corner like P100D (or P85D w/ + suspension), but not like a 911. Even if this will be a heavier hyper-GT and not a lightweight canyon carver, it still looks awesome and I can't wait to see final specs (and maybe own one).
P.S.
@ecarfan we should go for a drive sometime, both in San Mateo