I do a single infusion mash (1.25qt/lb) @ 152F for 60-70 min when I do BIAB with up to 8lbs of grain and get right about 80% efficiency every time. I use a slow pour over sparge with 168F water 1qt/lb.
I mill my own grain though, LHBS's mill too coarse so you have to buy more grain from them!