Maybe I'm just uninformed but I wasn't aware that the TT was saturated regarding lodging.  Very busy yes, but saturated no.  Especially if you're willing to camp.  When we've been there some of the campsites don't appear to be anywhere near full.  We use homestay and book ahead.  From a logistical standpoint it seems to me that the difficultly is in physically getting to and from the Island during the fortnight.  Especially if you're trying to get a bike shipped over.  It would seem to me that IF a TT related championship series were to become a reality it would have the potential inspire a lot more awareness and interest in a wider audience worldwide.  Those individuals would most likely be in our situation when we come over and would fly directly to the IOM and rent a car and not have the need/option of shipping a bike via ferry.  Therefore, the most obvious problem of access to the Island would be more or less solved for the increased number of people attending, as long as there were enough flights to handle the influx.  You would have to assume most of those people would be motorcyclists to varying degrees.  Maybe then it would also be more likely that due to demand businesses offering bike rentals would be more financially viable and hopefully reasonably priced.