Gluten free and lower carb oat matzah is available for those who need/want it.
6 oz of dry red wine (4 cups of 1.5 oz each) is all that is actually needed for the ritual meal (seder).
It is very possible to stay LC over Passover.
Dana Carpenter had a whole article on passover, and in a pinch you can always look into the "kosher low carb" mailing list and website.

danny