Best internet setup option

Weird scenario/question here. Working on finalizing my new house & remodeling.

Trying to plan a scenario where I have the best internet situation at a good price as well without sacrificing any internet speeds.

Overview: I have a main home & a back house where both needs internet. The back house would require hard connections to things such as PC/xbox/etc where-as wifi is fine in main home.

The main home has an all-in-one mode/router currently. Trying to think of best scenarios to get internet to this back house.

Was thinking of running two lines underground (digging a tunnel/etc) to the backhouse & plugging in a router/hard plugging pc/xbox/etc into router. The two lines would be just incase something ever happens to the one so I don't have to dig again.

Any thoughts?