I don't have the heated steering wheel. For 2017 that's part of the "Cold Weather Package" I don't have ... which would include just the heated wheel and front & rear floor liners, which I'm guessing are deep rubber mats. Maybe I'll buy a set of WeatherTech or similar come fall.
I haven't peeked under the seats yet, but if there are only wiring harnesses they must use thermoelectric cooling in the seats.
As for the Aviator, since I just got the Edge (under 27k miles) I'll not be making a change for some time unless I find this is a lemon. I plan to drive this into the ground, like I did my 1993 and 2003 Explorers. Well, the 2003 is not quite in the ground yet. Wife uses it as her winter car and drives a 2012 Fusion the rest of the year.
Poor me. I just got the Edge a few weeks ago, just before the stay-at-home orders in Michigan, and I've barely put on 100 miles. But it looks great in my garage. Ha. Ugh.