Ship one that uses Tunnel Broker to enable IPv6. Back when Teredo was a thing I wrote an article about how to turn a Raspberry Pi into an add on router for your IPv4 network. Essentially it would get a Toredo IPv6 prefix, then advertise the prefix to your LAN via radvd for stateless auto configuration. The effect would be that soon as you plugged one of these in it would instantly give every device on your LAN IPv6 connectivity without having to do a single thing besides finding a USB and CAT5e cable. Mostly was a proof of concept of course though I did run it like this for a bit. It worked quite well even if it didn’t give you your full bandwidth at all times.