Linda, welcome to the group. Don't worry about use of singular. Karen, for example, will have one suitcase for shoes, one for jackets, one for warm weather (Phoenix) and at least one more for the cruise. :D

As long as you don't have to pay excess charges on the plane, it doesn't hurt to overpack. There will always be someone willing to help with the luggage.

Again, welcome to LCT and looking forward to meeting you (and all the folks) in a few days.