Update. went to a local long time place in Toronto called Steelcase Tires in Markham, they fitted 16 inch steel wheels with no clearance issues and winter tires for the upcoming season 205/55R16 Pirelli Ice Zero FR. Hyundai is full of **** on this in order to sell 17 and 18. The cost was $1100 tires and wheels all in.
I have seen cases on the elantra sport forum where people purchased 16" wheels and had clearance issues or extremely tight clearance. I think it is highly dependent on the specific wheel design and offset. Yes, there are definitely 16" wheels that will work, but not all 16" wheels will fit. If buying used through CL or buying on-line, I'd stick with 17" for a winter set.
$1100 buys a nice set of 17" OEM take-offs and nice winter tires. Paying that much to roll around on steelies without TPMS doesn't seem like a great value.
For comparison, I purchased:
- 4 OEM TPMS sensors (take-offs from a 2018) on ebay for $35 shipped
- 4 OEM 2017 Hyundai 17" rims (take-offs from a 2017) locally through CL for $275
- 4 brand new Michelin X-ICE winter tires from tirerack for $670
- mounting/balancing was another $100
Total: $1,080 for a nice winter set that looks great.