You might already know, but you don't have to buy that odd Michelin size...one cross is 245/75R22.5 which is extremely close. Only a slight width difference of 9.25" vs. 9.65"...
The 245's are what I went with when replacing my Michelins. Bought them on Amazon Prime, so free shipping. Love's tire shop installed them plus spin balanced them ($40/tire) and I had brass extensions installed for the air valves ($7/tire).
This gives more options for finding a local tire store that might stock something. Look at truck tire stores maybe. You don't have to buy 'RV' tires.