Just FYI - if you have multiple memberships (with different member #s), MS will transfer points between those contracts without losing the 1 time per year transfer ability. MS looks at this as an internal transfer (all to the same member). As long as the resorts are the same in both memberships, the 11 month priority may be used for reservations - if not, all points may be combined at 7 months.
I just did this last weekend. I did not need to transfer all of the points from one into the other and the MS rep explained that I could still transfer the remaining points at another time (for a 2nd transfer to myself) or to another member (to use the once per year transfer allowance).
Your comments above explain very well what options the OP has in their situation. Personally I would make two separate reservations (one from each account) and ask MS to link them together. The worst case scenario would be the need to pick up keys on the changeover day - but no need to change villas.
Enjoy!