Bandwidth isn't that important with game streaming after ~40-70 Mbps, latency and jitter (essentially latency consistency) is.
Unfortunately there is no user-friendly tool to test for this. Most tests focus purely on speed, which can be tricked by various packet-loss-compensation algorithms, so you can score a "perfect" 1Gbps speedtest despite the connection cutting completely for a second.
Sometimes I forget that was ever a thing!
Edit: Nextgrid showed up as I was typing this and set the record straight. My faith in HN is restored.