Karen, what a great mission project you've taken on.
I looked up the weather in Haiti for December and January, and the lowest low temp I found was 66 degrees. Perhaps the quilts you send to Haiti should have a layer of flannel in the middle instead of batting. The quilts staying in MN will need batting, but the quilts for the warmer climate may be more useful with just the flannel. Perhaps someone from a warmer climate will chime in on this.
I wonder if you were to go to a sewing machine dealer that accepts trade ins, if you could 'borrow' or rent a bunch of their older machines that they take on trade ins. My guess is that many of those older machines get donated to overseas charities, so making a pit stop at your charity event may be feasible. Just a thought.
Another easy quilt is Warm Wishes. It alternates large squares with basically rails. The girls can strip piece, and then cut the rails, which will be quick and easy.
Best of luck with your endeavor.
Blessings,
Kris