"Premium wifi" is a Hilton Diamond benefit, and Marriott Gold and above get "enhanced wifi", however at IHG all membership levels only get "standard wifi".

At Hiltons, the wifi is often set up with a Hilton system which recognises your status if you enter your name and room number then automatically gives you the premium access.

If you are a frequent stayer at that property then all you can do is find a property which does offer faster wifi and then tell the management that you will be moving your stays.