Sounds like a plan, but like you said the game is late in development, so it wont have that same feeling of contribution to a indy project. Angle the pitch that support is needed for many more features such as X and X (im sure you had this in mind already).
A day or two after you release the demo, I will stream it when I can on twitch.tv. You have no idea how many people buy games from watching someone else play them, also you have direct access to someone playing the game, so you can get their thoughts and opinions.
Last build I played was a year ago and it gave me that xcom tingly feeling, so I already know its a great game. I was actually going to play and stream it tomorrow but I will wait for the demo
Kai.