What you describe is pretty much how I grow roses - two years of care and water then they are on their own. I have quite high and sandy soil which does not retain water well. Some summers we get rain but last summer we did not, from March to October, nothing. I don't think I lost a single rose to the drought even though I did not water any that had been in the ground two years or more. A few hybrid teas and floribundas died but around here that is considered normal attrition. I think most of the EarthKind roses would perform for you - if they are suitable for your zone. I believe I have all of them and they had no problem with the drought. A LARGE climber that grows faster than anything can eat it is Mermaid but I think she is a little cold-sensitive. Red Cascade is a little climber that I have not been able to kill by neglect or accidental herbicides and shredding. Left to her own devices, she would now be covering about 200 sq'. Seven Sisters has had much the same abuse is a very big plant and even repeat blooms!
Good luck - sounds like a fun project!
