Cable sizing

[Spoon]

Any info on the existing or new water pipes? Copper or plastic?

 

[TallPaul]

I can't help with the cable sizing, teletrix gives a good guide I was impressed you got that much detail - I find questions like this on this forum generally get answered with call someone in. If you want to do some maths yourself though you can use the TLC calculator:
https://www.tlc-direct.co.uk/Techni...230&length=12&submit=Calculate+Min+Cable+Size

But note that burying the cable de-rates the capacity.

Ultimately... your going to need to get someone in ;-) Or run big conduit so later whatever cable is needed can be pulled.

It sounds like you answered the TV cable question yourself, which I can help with - but coax of that length attenuated at TV frequencies is pointless - get a small sky dish on the side of the garage with freesat, or put a small USB dongle on a pi in the main house close to a good feed and steam to the remote location as you seem to have already found would be my suggestion. Other streaming solutions are available ;-)