I love fully local stuff, but the LLM part seems very expensive. Even for such a simple thing as managing our lights and music.

So, the simple things should just be voice command (not recognition, limited vocabulary), kitchen light on, what's todays weather (assuming you automatically download it and have it there, needs TTS like whisper). That can run on a recent potato. Somewhat more complex things need full voice recognition e.g. Play me x songname by y artist. Laptop CPU should handle that fine. You'll only need a full LLM for more general inquiries, e.g. What mess has Trump made today?, which will need web access seeing as small LLMs don't have a lot of world knowledge (although you can self host Wikipedia and point it at that).

If you have a desktop computer and a GPU with 16+GB VRAM (or even smaller using RAM and a MoE LLM) that'll do the job with reasonable smarts e.g. Qwen 3.6 35BA3B, Gemma 4 12B or 26BA4B. You may have to wait a minute or two. Mine pulls around 55W at idle (7800XT) and does double duty as a NAS and gaming rig, or you can have it sleep most of the time and let the laptop wake it up when necessary.