The "slightly lower range" of the P versus the AWD is an artefact of the exact wheels used in WLTP tests (which, since the P in Europe was sold exclusively with the Performance Upgrade Package, used the 20" Stiletto rims with more grippy tyres for the "P" numbers, and 18" rims with aero hubs and Michelin Primacy MXM 4 with less rolling resistance for the AWP).
I doubt they're going to redo WLTP tests for P- with 18" aero wheels, which is why you see the numbers you see. A manufacturer is always entitled to underestimate the range if he wants to ;-).
In recent EPA testing they tested P with 18" aero wheels as well, and the difference in range between P- and AWD with the same wheels is zero, zilch, nada, zip.
So if you want "as much range" as the AWD, just buy a P-. If you want less (but higher performance wheels) then buy a P+, a P with the Performance Upgrade Package.
You can also get 4% less range on motorways by getting rid of the aero hub caps, if the performance upgrade pack is too expensive ;-).
Incidentally, the WLTP numbers were slightly downgraded by Tesla in the marketing literature with respect to the WLTP tests, but one reason is that in Europe the cars tend to come with the slightly more grippy Michelin Pilot Sport 4 (not 4S) summer tyres, which have slightly more rolling resistance but better grip than the Primacy MXM4 all-season tyres.
Incidentally, the current "no 19" wheels" is because Tesla is severely production constrained on them and is trying to satisfy a bucketload of 19" orders in Europe, so the last thing they want is more people to order these, at least temporarily.