I'd be more concerned about the range you get on a 70D vs. a 90D than about the presence/absence of the premium interior option. Unless you plan this for a local urban area driver only.
Peter+
My only (once/twice) year road trip is from O.C to SF (about 430 miles) and I figured I would have to stop twice anyways even if I had the 90D (Buttonwillow & Harris Ranch Superchargers) provided that I may have to wait a bit longer to charge the 70D.