There is no need to improvise something as inexpensive as a tire boot, when you can get good ones for a few bucks: https://www.parktool.com/product/eme...tire-boot-tb-2 And the Park boots have a self-adhesive so they can't slip out of place.

I once rode 20 miles home with a tire booted with a piece of old innertube, and it was not fun watching the boot bulging out the side of my front tire, on the verge of snagging the brake pad. The problem was the lack of reinforcement to prevent stretching like a balloon.

Years later I had another flat caused by a slashed sidewall, but this time the rip was large enough to put my thumb through it.I had the Park boots with me, but had little confidence they could deal with such a large hole, and anticipated a 6-mile walk home. I gave the Park boot a try, and to my pleasant surprise, it held.