I think it would be wise to determine what the fault is first. there are many problems that can affect internet speeds including over-subscription. just because someone is suffering from slow speeds due to utilsation, doesn't mean that it is the sole cause of slow speeds.
I would test the internet speed with a device connected directly to the hub by ethernet cable, testing during the day and again during evening peak.
If you are getting headline wired speed during the day and poor speeds only during evening peak, then it looks like a contention problem, If you are getting poor wired speeds all the time, then it looks like a technical problem which can be fixed relatively quickly.
Wireless is affected by maby external factors making it unsuitable for testing the actual connection speed accurately.
If VM confirm it is a utilsation problem, then I would leave as it is very unlikely to a quick fix.