Scene for automatic bed-heating

[w_vier 0]

I have a heating bed sheet on my matras, that preheats the matras for the cold nights. It takes about 10-15 minutes to heat up the bed, so i would like to have my Fibaro to heat up when it knows i will go to bed. Hopefully someone can help me, so far i've done most of my automation through block based scenes, running into some limitations now as i would like to reach higher levels of automation.  Thanks in advance for thinking with me. 

Conditions:

- only when i'm home (GPS for my phone)

- only between 21:30-01:00 (this one cannot be done through blocks i'm afraid)

- only when outside temperature is below 11 degrees (i would like to get this value from the internet, as i have no sensor outside today)

   - if to difficult/challenging, i can buy an outside sensor of course 

- only when it's NOT already once activated in the past 3,5 hours (this one can also not be done through blocks i'm afraid)

 

Trigger(s) --> This one is tricky, as i would prefer to not have a scene continuously running, but a real trigger, for example through a variable/parameter. 

- lights going off downstairs (already connected to fibaro)

    - i think this requires a variable to be part of the 'lights-out-scene' in the living room, otherwise i'd have to continuously check the status of the lights

- alternatively i can use the lux sensor i have in my livingroom ... however, sometimes i have to come down again after some time, and turn the lights briefly on, so that might impact this trigger?

 

Additionally i would like to have the heating sheet turn of 2 hours after being turned on. 

 

I hope there's somebody here with suggestions