I am not a coach around here but I am pretty sure they would tell you to start now with the transition month and repeat a base training month or however many weeks you have extra until you can continue the plan and taper as prescribed so your plan ends with Mount Blanc in July.
The other option would be to get the 24 week plan and do that. It seems like that would get you right on the schedule to climb in July. The cost of a well tailored plan is trivial compared to the trip to Mount Blanc and all that.
//Jason