I have a spare (full size) steel wheel from my 2010 Corolla that I use as a spare on my 2016 Corolla. Same bolt pattern. But they are totally different sizes. My steel wheel is a 15" rim with a 195 tire. The alloys on my 2016 are 16" rims with 205 tires. Tire height appears to be the same. I used the steelie for a week or more when I tore a tire up last year, and had no issues.
Another thing to consider, is if they are not the same height, it will throw off your speedometer. Not by much, but it will be noticeable. I ran taller 65 series tires on a Mazda years ago, that was supposed to have 55 series tires, trying to save a buck. Threw my speedo off by about 3 or so mph, and I ended up getting a speeding ticket.