For DVC members this might not be particularily difficult except at Holiday/Peak time. However, the OP is asking about availability for an Intrawest member to book at BLT. I would expect the number of units available would depend on how many BLT owners used their points to trade out of DVC. I am quite sure that Intrawest members would not have access to the full availability that a DVC member would have. I would expect the same difficulties that I have had in trying to trade my DVC points to an Intrawest resort...
Every time I have tried this (more than 5 times) I have been faced with no availability, from the opening of the booking window until I just could not wait any longer for something to open up, and these have been at non-peak times for the resorts I have tried to get.
For the OP, it might happen, but I would highly suggest a backup plan.