I don't think it will work. First, the spare tires provided in Europe/Australia in the manual (per ZB's post on Jan 5 in this thread) are T125 70R17. The Envision spare is 20mm wider than this. While it might fit in the spare tire well, judging from all the extra stuff I was able to pile on top of my spare. But OEMs only test and vouch for the spare tire sizes they include for the model of car.  Second, the extra width MIGHT create issues when it is actually on the car: rubbing somewhere against wheel well, brake caliper, something.
If you have possession of an Envision spare, then I'd try to test mount it and replace one of your front tires. By doing this, you can see if there is any interference or rubbing -- and also check if the lug pattern matches up, too.
If you don't have an Envision spare, I'd suggest going with a very available T125 70R17 spare from a 2018-19 Chevy Equinox or 
GMC Terrain. This is the spare tire the consensus on this board agree is a good choice. Plus GM sold far more Equinoxes and Terrains, so availability and pricing should be better.
That's my two cents, anyway. If you have it, try it out. If not, go for a sure thing.
Anyone else have any thoughts?