Thanks everyone for the responses. I am still torn on what size tarp to get, I keep going back and forth. The 8.5' square tarp would be lighter and should be adequate especially combined with a bivy. On the other hand the 8x10 would be more roomy as I am rather tall, and might provide more protection in a bad storm. Guess I will keep thinking on it for a few days. I just need to put an order in soon to try to get my near the start of the season.

Would the larger tarp be more difficult to pitch tightly on account of its increased size?