i did not read every reply to your question but i would take the largest tarp i could stuff into my BOB..i took an 8x10 tarp on a canoe trip many-many years ago with the idea that would sleep under the canoe with the tarp to compleat the shelter.i ended up using trash bags opened up to give myself more cover.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.