Did 2 weeks in China last year and that was the longest I’ve had away. Work was fine. I just ran two weeks behind schedule for a month and then it was all caught back up.
I find that in general, customers on a monthly service (not 4 weekly) don’t really know when to expect you anyway, they just know once a month, and are just happy to have someone regular.
You’ll always get the occasional oldie that puts in her calendar when your due next mind you.
To be honest, 7 days away for me is normally enough. I’m looking to get back into a routine after that.
I also do long weekends scattered through the year when I feel like a need a break. A Thursday to Sunday break really lifts the spirits sometimes.