Re: It's the most (energy) wasteful time of the year
There's control protocols DALI and DMX (and probably others) which will control the lights - using off the shelf devices. You can (AIUI) also get wireless bridges for both - not necessarily needing the overhead of "over-IP".
So equip your lights with DMX or DALI controls, use a wireless bridge from house to location of lights, run a controller on (for example) a RPi and job done. AIUI having looked around at what's available but not actually having implemented anything yet, what you are after should be easy to do with off the shelf bits.