Add to the March closures list:
People Mover (2/10-3/27)
Pinocchio's Village Haus (2/17-3/30)
The Plaza (2/17-3/15)
OP, I'm going in March, too, and I was also disappointed at the closures extending into such a busy and expensive time of year. I'm surprised that the second week of March (when we're going) will have two restaurants in MK closed -- that's typically the second-busiest week of Spring Break.
I'm not sure what you mean by "winter."

March isn't winter by Disney standards (except for the first week). Peak season pricing starts March 7, with the second-highest rates of the year -- higher than even Thanksgiving. Spring Break crowds will descend the second week, with crowd levels equivalent to summer. OP's point -- that they're paying peak prices with multiple closures -- is a valid one.