I have always believed in the two dry bag method. Similar to this combination. Two Sets of Rok Straps go under pillion seat to frame. http://www.twistedthrottle.com/drys...ular-packing-system-in-black-grey-orange
One bag (the bottom bag, usually heavier) holds everything for outdoors/outside the tent. Tent, ground cloth, extra shoes, cooking items, extra liner/light jacket, kermit chair etc. The top bag holds everything needed in the tent: bag, mattress, pillows, lights, fan.
Side cases hold the clothe, shave kit. The top case the tools, tire plugger, light food, extra water, rain gear.
I strap bags similar to this; https://www.google.com/search?q=pics+of+dry+bags+strapped+to+motorcycle+seat&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj7u6ryh5zYAhUELSYKHSeICikQ7AkIQg&biw=1530&bih=714#imgrc=xhCncXoIBjgcUM: and use them as back rest. Straps can be put under pillion seat when not needed.
Tank bag, for light snacks, first aid, odds and ends.
I unstrap at destination, keep inside bag out of dirt or on table or on seat of bike while I set up tent. The outdoor bag can go on ground and I unpack the tent first, get it set up, and then toss the clean indoor bag inside tent. Pack up is breeze. I pack inside bag first from warm tent get dressed and all that left is outside bag to pack. Takes about 15-20 minutes.