I'm sure different approaches work for different people. I've never packed a separate bag for hotel overnights to avoid taking in luggage. It seems simpler for our family to keep our individual things together. Each person packs clothing in their bag/suitcase and I carry a family toiletry bag with all the basics and everyone's toothbrushes. I do like to pack in outfits and tend to roll them (top, bottoms, unders and socks) together, secured with a rubber band. Take a large communal laundry bag. For snacks each kid gets a labeled gallon ziplock bag at the beginning with their assortment for the first day. It's great because all trash can be placed right back into their bags to be emptied and replenished in the evenings. I carry the bulk snacks. I don't tend to pack meal food if we are staying in multiple hotels, other than breakfast. My kids are restless and don't do well hanging out in hotel rooms so we try to spend a limited amount of time there and eat in restaurants or outdoors. For breakfast, healthy muffins or baked oatmeal work well earlier in the trip. We do cereal and milk with fresh fruit if there's a grocery store nearby.
Hope you all have an amazing trip!
Mom to Two Wild and Crazy Boys and One Sweet Baby Girl