Grandparent Concerns

My husband and I are very fortunate to have a strong support group around us as we welcome our second child, however I find myself stressing a lot more than I would like over how to handle the overbearing grandparents. My due date is Christmas day although I know I will have him a week before as I'm having a c section, I'm so nervous about the holidays. My mother in law is wonderful but she goes way overboard for Christmas with our Son who is 6 and I have a terrible time trying to find a place for all the stuff she gets him, he has three other sets of grandparents too plus a great grandma. I have tried all I can think of to tell her without hurting her feelings to please not get so much as I'm constantly mentioning how little room we have at home for it but it haven't gotten through to her. I'm also stressing over how to politely address grandparent visitation. With my son now, she has always wanted to keep him for a whole weekend, at least once a month and I just feel like that's excessive. I don't like it and I never have. She only lives 45 minutes away. I definitely don't want my infant going to spend the night for an entire weekend. I've tried discussing with my husband but he gets defensive and tells me we will worry about it when that time comes. Usually when I try to address her, she gets upset and says I don't like her and that's not the case at all. How can I address this without any hurt feelings?