Previously I described some of the issues regarding getting the internet working at our new house. Well, it seems like I've finally found a solution!
Using a WiFi extender was not successful, as the average network speed would still be around 10Mbps. I considered getting a second ASUS router and setting up a mesh network, but initial testing using the existing router showed it would peak around 60Mbps and maybe not be that reliable.
This morning I went and bought anAV2000 Gigabit Powerline ac Wi-Fi Kit . It's theoretically capable of carrying up to 2Gbps over electrical wiring, with 802.11ac WiFi built in. Guess what, powerline networking is amazing! Given that our house was built over a century ago, I was a bit worried that the electrical wiring wouldn't be up to the task. However, setup was super easy and the link between the two powerline units is around 670Mbps!
My actual Internet speed is only around 40Mbps (while I'm paying for 78Mbps), but that is a whole other issue.