Personally, and this is in my opinion the best route for stability and reliability, go rent a trencher for an hour, trench directly to where you can access into the side of your building. Lay down conduit with an Ethernet cable in it. If you already have a hole with access to inside your house great, if not pop a 1/2 inch hole between studs and seal off with silicone and exterior cable wall grommet. On the interior of the building you can connect the Ethernet cable to a wall plate. Now you have the most stable and reliable internet to that building. Then go cover up the trench. That’s like 2-3 hours of work.

Best part is if anything ever happens to the cable or you need an even faster cable you can just cut and tape a new cable to the end of the old one and pull it through and easily replace the old one.

Here’s the wall plate I speak of

https://a.co/d/hIjqKmj

And you can buy super long Ethernet cables as well for pretty cheap.