You can still do a High Heat cook on it, I do them all the time. I usually have anywhere from 8 to 9 lb Butt, and they come out great, you should have no problem with 10.5 lb picnic. total cook time for me is about 5 hours (3.5 @ 350, then 1.5 hrs wrapped in foil @ 350+) if you decide to go HH...