I run a 2gb pi 4 with HA, Pihole and Emby server. Normally runs at 6% load, 36% memory. Any device on the local network can see the HA pages. Phone and tablet can access via wireguard vpn .

Wireguard vpn on raspberry pi running a WordPress home site. HA on another pi inside network .

I use Wireguard as a vpn running on a raspberry pi. Phones, tablets and laptops can all operate the local HA as if still at home.

I use a Raspberry Pi as a Home Assistant server. Some lights are controlled, but mostly it monitors temp, humidity, solar panel output, electrical load and our UPS. Not wishing to have a panic should the pi fail, I retained traditional thermostats to ensure a basic level of heat energy goes into the underfloor wet heating. If the weather forecast predicts lower temps, the Pi can add extra time to the day’s heating cycle. The Sonoff and Solis integrations work well and are the only items requiring internet access. Otherwise, everything else is local. I use a ZigBee hub to keep most of the smart devices off of our Wi-Fi. I have a ZigBee/IR blaster on order to see if we can dump surplus solar power into an air-conditioner.

Aye