It's a little trickier making ressies when you own at two resorts. We own at BCV and VWL. When we stayed at BCV in May, we booked at 11 months out for as many nights as we could with the BCV points, then waited until the 7-month window to complete the ressie using the VWL points. We were only going once this year. Another option would have been to book BCV at 11-month window using 2004 BCV points and borrow enough 2005 BCV points to complete the ressie. Then we could have banked 2004 VWL points to use in 2005.
Or could have booked several nights at BCV and several at VWL at the 11-month window and transferred to just one resort at the 7-month window if it is available.
It can be done, just need to put on your thinking hat!