Going to answer my own question - and ask a few more.
With snow in the forecast, I took my winter tires (already mounted on rims) out of storage. These were from my (gas powered) 2016 Kia Soul SX, so are 235/45 on 18" wheels.
These ended up fitting just fine on my 2020 Kia Soul EV Limited (stock is 215/55 tires of 17" 'pizza dish' wheels).
I find my Soul EV handles much better with these tires.
It's a shame Kia doesn't offer or use these on the 2020 EV. It might shave a few km off the highest-achievable distance on a full charge, but worth it for the improved handling benefit.
1. TPMS NUISANCE
The 2020 EV Limited has a Tire Pressure Monitoring System (TPMS).
My 2016 Kia Soul SX did not, and neither do my (or most) winter wheels have (expensive) TPMS sensors. After about 30km or so of driving, the TPMS warning light came on. I cannot disable this or turn it off. There doesn't appear to be any setting or switch to do this. Earlier Kia models refer to a physical switch near the steering console, but the 2020 Soul EV doesn't seem to have this. The only TPMS setting in the menus I can find is to select the units of pressure to display readings in.
Anyone know to to reset or disable TPMS on a 2020 Kia Soul (EV)? If not, I am going to be staring at this warning light for around 6 months.
2. JACKING PROBLEMS
For some time, Kias do not come with a spare tire or even a car jack.
When I had my 2016 Kia, I bought a small 2-ton bottle jack. I used this many times with my 2016 Kia Soul to swap tires.
The same bottle jack on the 2020 EV could not really get enough height/lift to safely elevate the wheels. I had to block it underneath with 2x4.
The metal at the car's jackpoints on the 2020 EV is also weak/flimsy. On three of the wheels, and using six different spots, the metal at the jack points BENT when using the same bottle jack (which repeatedly worked perfectly on my 2016(.
In one case, this metal failure/bending caused the raised jack to fall over, causing a potentially very dangerous and damaging crash (which did damage car's plastic skirting).
I now plan to buy a scissor jack or a larger bottle jack.
3. CHEAP PLASTIC WHEELS
You have to be really careful using a lug wrench on the stock "pizza dish" wheels. It's super easy to scuff or scrape them. The first couple bolts I took off, I caused minor cosmetic damage around the lug nut holes - and had to be really careful of the angle I held the wrench at after that.