I know nothing about what a BPI R4 is. My take : let the router be a router : don’t run container(s) on it. If you need containers: Take a x86 box, Run an hypervisor OS (e.g. Proxmox), create a VM for your router OS (openWRT, OPNsense, etc.) and pass through your Network Interface Card(s). Then run your containers on the host OS or in a dedicated VM.
Lol. I (Quebecer) have 200a panel, electric resistive heating (in every room including a detached garage, no central AHU) + mini-split heat pump + electric car charger + electric water heater and my power demand never go above 15 kW (which equates to ~ 62 Amps).