The fuel powered heater is a Webasto unit installed under the front right footwell - drivers side for me, passenger side for you.
On mine, there is an option to turn it off in the heater controls and on my A8, I could set a two event timer over a daily cycle. It may well be possible to set it up the same way on the Q7 if it is turned on using VAG-COM.
On my wife's A4, there is an electric heater which is pretty good really, nearly as quick to heat up as the Webasto one, but it has no timed operation possible due to battery drain.
For the Webasto one it is possible to install a remote control via IOS or Android app and an SMS service to the car. I found one but I cannot really justify the cost - about £250 all-in.