For starters, I always go on holiday in the winter. Mine feed every three-four weeks then, so they don't mind if I'm not around with food. I make sure they've all pooped before I go, so there's no spot cleaning to do.
I'm lucky enough to have a mother who loves snakes and she drops by twice a week to check/change water.
Any that are not in a condition to have reduced feeding will go to "boarding kennels" at my local reptile shop for £5 per animal per week.
An unattended heatmat can overheat if it goes wrong (I've had it happen) so I would always recommend using them with a thermostat, which should prevent accidents. As I'm in the UK, leaving the heatmat off would only be an option for about three weeks a year!