Laurie!
I'm in South Central Kansas also, and my clematis are all in full hot windy sun. Not all of them are mulched--but they do have other plants shading their roots. I don't have irrigation, and they do ok, but those that are planted closer to the faucet definitely do better.
Are you near Wichita? I'm east, near Andover.
Did you get your clems from Arnolds?