Instead of ssh I use wireguard directly. It’s a simple protocol based on public/private keys with great performance and security.
Wireguard is stateless and establishes connections really quickly on demand. This means the battery isn’t impacted even though it’s always on, since the VPN doesn’t have to maintain a constant connection. At least that’s the case if your routing only a specific subnet (e.g. 192.168.1.0/24 and not all traffic through it 0.0.0.0/0).