I have $5 Strong VPN and they are very strong. I don't understand how the free VPNs make money and would steer clear of them. Any of the top rated services (per a reputable rater) will be fine.
When I was living overseas, I had an old router that I reflashed to DD-WRT and it was the router that was logged in to the VPN. So everything on my wireless network was on VPN. Now, I only have VPN installed on my laptop. I haven't had to use it to poach bike races lately but a good reminder from
GrainBrain that I can. Easy to tell the laptop to pretend to be in the UK so that my GCN+ works, and then Chromecast from laptop to my TV.
If you are trying to do something like watch through Roku (which, unfortunately, GCN does not offer), you will need to go the VPN-capable router route since you can't install the VPN app to Roku or your Smart TV. There is some info on those various options at the Strong VPN site, which I think generally apply whether you use them or another service. Speed, cost, security, and how often you can flip your location are distinguishers between the services.