I have a Class C -- 2018 model E450 -- and I am one of those "be prepared" type of folks. I ordered a Class C spare tire holder from eTrailer. It's not cheap, but that's because the tire/wheel for a C is HEAVY. The holder is extremely heavy duty.
For the Wheel and Tire, I went to my local Ford dealer, got the wheel. I saw that you can buy the wheel online as well..eTrailer.
Call or search eTrailer....they have what you need. The great thing about the spare tire holder is that it uses your hitch...and it has built in another tube for you to still tow. We can still flat tow our Jeep with the spare installed.
And, yes, all told I'm thinking it was about $800 for the holder, tire, wheel. Not cheap, but worth it.
Also -- I carry a large 5T bottle jack. If I had to, I could use my boards and the jack to lift he RV just enough to change a tire. We have auto leveling system (hydraulic), and I've tested this in driveway...I would use that system to help stabilize and lift as needed.
Lastly, I bought a middle of the road (about $100) cordless impact just for changing tires. Right out of the box, after battery charge, I could not believe it....it actually was able to remove ALL LUGS from one tire...and reinstall (of course I used a torque wrench to finish it out).
Point is...I bought the stuff, then "practiced" using it to ensure I had what I need. I'm an engineer by trade, so blame that on the fact that once I have a plan or theory, I must test it to be sure.
eTrailer....call 'em.