+1 for the Michelin P4s- not a run flat tire but a 300 wear rating and all around great summer tire. The 4 does not refer to this as a 4-season tire. I think they're also quieter than the OE tires (my OE run flats lasted 10K miles- so I don't think you're pushing yours too hard).
Infrequent use and UV exposure increase the rate of "dry rot" in tires. Look at the tires most often exposed to the sun in your carport. Lots more info here-
https://www.wetrytires.com/tire-dry-rot/