Yep. I would have chosen 19s or 18s if the 1st Edition had choices for wheel size. Once the ID.4 has been in production a little while, we should have data to compare and could always swap wheel sizes if there's a big difference. Aerodynamics of the wheels matters, too, so wheel design impacts efficiency as well.
I too, would have preferred to have 18" wheels over the 20" in my FE reservation. I'm trying to figure out if I can swap wheels/tires with a Tiguan owner when I get the car--assuming the bolt pattern/offset for the Tiguan is the same. Failing that, I'd be happy to swap tires with a non FE with 19's.
The ID3 reviews with 3 wheel sizes were not significantly different. VW said the same thing in car's unveiling, basically there won't be a big drop in range with 20 inch wheels. The only explanation is that they engineered the larger wheels better, so they are more or less the same weight. But who knows.
Here is one datapoint on the impact of different wheel sizes: “Although Tesla is more forthcoming than most automakers about providing range figures for the various wheel-and-tire combinations it offers—it is only required to report the most popular option—it does keep the occasional tidbit to itself. For example, based on the road-load data it has submitted to the EPA, opting for 21-inch wheels on a Model S Long Range Plus will cut the range by nearly 80 miles. You won't find that information on Tesla's website.”