You can actually use a computer as your router. It takes a bit of know-how, and a machine with two network interfaces.
Here’s how I’d do it:
Get a Raspberry Pi or other ultracompact linux PC (if you happen to have a Linux-capable machine laying around, that’ll work too). One requirement: you need two network interfaces. This would work: https://www.seeedstudio.com/Dual-GbE-Carrier-Board-with-4GB-RAM-32GB-eMMC-RPi-CM4-Case-p-5029.html
Assuming you want wifi, you may want to provide that separately, as the RPi’s wifi antenna will not offer great coverage. I’d use an Eero mesh or a set of Unifi APs.
Install and configure Speedify’s Linux client. How do I install Speedify on Linux (Ubuntu and Raspberry Pi OS)? - Speedify Knowledge Base
Configure iptables to route traffic between the two NICs as needed. How to make RPi a router with firewall? - Raspberry Pi Forums