I just talked to Rease about our forthcoming 15b that is due in the summer.
For a nominal charge, Rease is able to offer an extended version of the 15b. I believe that he will call it a 17b
After much soul searching and discussion, my wife and I have abandoned our dream of a 15 footer and have switched in favour of the extra space in the 17. The rest of the options will remain.
This also moved our due date up to the start of summer rather than mid-August.
I believe this is called "2 foot-itis".