Another question as I am preparing to replace tires on my fifth wheel. I am replacing due to age, not due to wear. Question is with regard to the spare. I know the best thing to do is replace all 5...
After a blowout and realization that I had problems with other tires (all due to age, tried to squeeze 1 more season) I had to use my spare which was also old. It worked fine for the remainder of my trip, a couple hundred miles and was still OK, but I replaced all 4 with new and used one I had to buy to get me through as the new spare. I think you will be OK with your spare, or use one of the 4 for a new spare and change 1 out each time you put new ones on the ground.