You can rig larger tarps (eg, 10x10 ft) into fully enclosed pyramid-type shelters although perhaps lose some of the weight advantages. Or, depending your priorities, consider a shaped tarp (with inner net tent) which can really have some of the best benefits of both double tent and floorless tarp. I use a solo pyramid shaped tarp, usually kept floorless while awake and then double-wall while sleeping, for ~1.5lbs and 2.5L pack size.