Hector

Paul I think David meant "b***cks" as in "Oh darn it" rather than calling JK a liar

I wouldn't do anything that involved me driving somewhere and doing something, for less than £60. Sure, the going rate for a turbo drier is under a fiver but your time and diesel isn't free!
It isnt't the landlord or agent's problem if carpets need a dryer leaving behind, it is your cost to bear. Better off avoiding lengthy drying.
To be honest you're better off turbo drying as you clean and leaving the carpets just slightly damp, then locking up and forgetting the place. No problemo as long as they're just off touch-dry when you leave them, even in an unheated house in winter
Take a turbo into the first room you start extracting, clean a little bit then plonk it on there... work it back as you go. With two fans I can get most of a 3-bed house touch dry before I leave working like that.