If you feel confident the price won't go up and it's Latitude FP:

-- buy the flights you need 2-3 months from now, as full Latitude refundable

-- buy the FP 48 hours before these flights

-- cancel and refund your Latitude bookings

-- book the flights on the FP

Make sure there are adequate Latitude (M) quantity available to do this. Use ExpertFLyer to monitor.

I once suggested to AC that they allow a FP purchase to take effect at a date 2-3 months in the future. I think this is beyond the ability of their IT to implement, hence, doing this.