I understand the no wind and getting home dilemma. For that reason, the board that use in most windy situations has enough volume to give me just a little bit of float (deck just dry) so that I can uphaul or sail in 0-5 knots without struggling.
The upside is that I can easily get home regardless of the lack of wind.
The downside is that the board is too big on windy days, but manageable.
My usual sailing site has a big wind shadow near shore (25 knots outside and holes with as little as 0-5 knots inside).
I have a smaller "sinker", but I only use it at sites where there is solid wind with no holes.
If you know exactly how small you can go and still have a "floater", that's your board.