As above please - any advice on AV senders?

I've got myself a birdbox camera so I want to get the signal into the house. I've got 20m of cable that I'm thinking may get me from a suitable tree at the back of the garden to the back of my garage (separate to the house and set further back from the house into the back garden) from where I should be able to get power etc. to a sender. It'll need to go through two or three solid brick walls to the receiver and not interfere with two dect baby monitors, a dect phone and my wifi...

Oh and cheap would be good as I can get another 30m of cable for a tenner or so but that would mean drilling yet another hole into the house.

possible?

Stick with a wired solution..