The key statement in this policy is:
The strange part is that the MOR-EV program never really defines "base MSRP" anywhere, so it's unclear whether it's the sticker price (which would include options) or the trim-level pricing before options. The only thing I can find in my quick scan of the MOR-EV Implementation Manual (last updated in February 2016, available
here) is a footnote next to "base MSRP" that reads:
If you go to fueleconomy.gov, you find a footnote there that says that price information is provided by Edmunds (cue wild-goose-chase music). That said, it seems that Tesla is one of the OEMs whose MSRPs are "not reported" -- if you pull up the Tesla Model S, they break it down into the different trims (70D, 90D, P90D, etc.) but there is no MSRP information. So, that means they'll be going to teslamotors.com for their MSRPs (cue wild-goose-chase refrain).
However, if you pull up a 2016 Chevy Volt, it shows you an MSRP range of $33,170 - $37,520, i.e., the base MSRP for the LT and Premier trim levels. Given that a fully-loaded Volt has a sticker price around 45K, it makes me think that MOR-EV's restrictions do not include include the price of any options that you add onto the car. (If they did, I would assume their wording would simply be "MSRP" rather than "base MSRP"... but again, our lawmakers aren't always as clear as they need to be...) Under this reasoning, the "base MSRPs" for the Model 3 would be 35K (base battery), ~40K (base battery + D), ~48K (max battery + D), and (hopefully, for the sake of your fully-loaded aspirations!) ~58K for the P(max)D.
Curiously, there are no "entry-tier" EVs (even at the upper end) on the MOR-EV list that exceed $60K fully loaded. (The i3, B-Class, and A3 e-Tron all max out around 53K.) In other words, there is currently no "unit test" that we can apply to this question... but I imagine the Model 3 PxxD might change that.