Modern skinny spare for older mopars

None of the cars mentioned are going to have a skinny 23" tire. I think in order to get a skinny tire that diameter you'll end up buying something like a Coker Firestone F560 125-15 or 135-15 tire.

But how does 23" match up to the other 4 tires on the car? Seems way small to me.

My rims are 15x7 and I have 25” tall tires. I just want a spare to get me off the highway.
It’s for “just in case.” But if I don’t have a spare- I expect a flat.