I say, "GO FOR IT!" You will enjoy quilting a whole lot more when you have room to get around your quilt machine.
When we looked at the house we bought last year, that is the first things my husband said, "You can have the master bedroom for your sewing and that will also give you your own bathroom." So my husband and I have our bedroom in the other bedroom downstairs and our boys have the two upstairs bedrooms. It has worked our perfectly.
Angie