Those standard range RWD models are sneaky... I almost did the same thing myself from the "manage" page.
However, your spot with EDD is 2/26-3/31 can potentially have you missing out on 3750 tax rebate.
So think hard before you give up the RWD version.
In terms of range, it is pretty much the same. MYLR charged to recommended 80% level is only 264 miles of range, while the RWD charged to recommended 100% is 269 miles
On the long trips, you anyway would have great supercharger support, so probably it will be an extra 20 min in a 5 hr trip.
Get the AWD MYLR only if
(a) You are willing to take the 3750 risk, and
(B) Only if AWD is important for you as compared to RWD
On the plus side, the RWD might be able to pull some donuts that MYLR can't