IMHO this is not a technical problem but a strategic issue. A consistent internet access, may it free or not-free - meaning a consistent way of getting access throughout the IHG brands, maybe a consistent pricing structure and a way to use internet time purchased at one property at any other property as well. Even if they cnanot have the same provider due to provider availability, they can still create an additional access layer to make it look the same in every hotel. ALso as a platinum member traveling alone, for me it would often be nicer to have free internet instead of a room upgrade or so.
IHG does not seem to realize that this internet access easyness and consistency would be a great value against competitions and also binds the cusomers to the group.