Part of the confusion on the temp spare tire/wheel size is due to the fact that two different sizes were originally used by Honda, for different non-hybrid models, based on front brake rotor size. At least this was the case when the 10th Gen cars were introduced in 2018.
Back then, lower-trim 1.5T cars (with 11.5" front rotors) came with a T135/90-16 spare. But all 2.0T cars and some higher-trim 1.5T cars (with 12.3" front rotors) came with a T135/80-17 spare. Note that ALL hybrid trims (at least in 2018) came with the larger front brake rotors (12.3").
For that reason, I think that the best tire/wheel to get for a hybrid is the T135/80-17, which can be mounted on either a front wheel, or a back wheel. That said, the T135/90-16 spare will mount fine on the back.
For safe handling purposes, it is usually better to avoid putting the temp spare on a front wheel, anyway. (If the flat is on the front, first put the temp spare on a back wheel, and use the freed-up regular wheel and tire from the back, to replace the flat on the front.) That said, if you are just going to slowly drive a short distance, having the ability to mount your temp spare on a front wheel avoids this need for doing a "double tire move", if you get a flat on a front wheel.....
Note that back in the early pages of this thread, some posters said that the 16" temp wheel and tire DID fit on the front wheels of their hybrids, but that might be a "just barely" situation?
Why didn't Honda simply spec the same 135/80-17 temp spare for ALL non-hybrids, including the ones with the smaller 11.5" rotors? Who knows....
One other comment: Back in 2018, anyway, the foam insert that fits inside of the temp spare (to hold tools) was a different part, depending on whether the provided temp spare was the 16" one, or the 17" one.
Bottom line - if you want to order the right parts, "pretend" you are ordering replacement parts for a 2.0T car, rather than a 1.5T, and you will be safe.
In this long-running thread, it took until the 4th page or so, before the info started being pretty well sorted out..... I don't think things have changed since then, unless (perhaps) all non-hybrid cars now get the same set-up (I don't know about this, one way or the other....)
Three "tips", based on my ordering experience from 2018:
1. The prices of the temp spare tire itself, vary tremendously, depending on tire brand, so shop around. Kenda seems to be pretty low-priced, but some other brands (Goodyear in particular) are quite a bit higher.
2. I found that shipping costs were quite high for the foam insert, of all things (I guess based on size, not weight). So in the case of that part, I found that it was actually cheaper to buy it at a dealer, rather than from an online seller. But the online discount sellers were cheapest for all of the tools, the rim/wheel, and for the tire itself. (I then paid $8 to have a nearby America's tire mount the tire on the rim.)
3. Buying a spare and wheel used, off of another model (different than a 10th gen Accord) can be an inexpensive way to go, but you need to be more careful about sizes, etc.
I also don't have an opinion as to why Honda omitted a temp spare for the hybrid cars, in the first place. I tend to think it was a weight consideration, rather than concern about the spare being pushed forward into the under-rear-seat hybrid battery pack (in case of a rear-end collision). That's because I have never seen any sort of official "do not do this!" warning from Honda about putting a temp spare into a hybrid. And some Honda dealers seem very willing to help customers who want to do it.