I space mine longer Daz but I’m charging more per clean m8,I use hot water like you a few extra weeks make no difference at all.
I have a lot of work all priced well for the average plodding day and very well priced stuff I mix in if I want to make money up for weather etc,it’s like I’ve always said if you are round knocking there door down for payment every 4 weeks or a month or debiting money out of there account on a frequent basis it’s easy to say no thanks or push you back longer anyway,I call less often and charge more when I’m there they need a clean so they don’t mind paying more per clean.