We typically aim to be at the entrance to the RSR queue by 7:55 ish. I think as long as you beat the non EE stampede that arrives shortly after 8 am your wait should be 20 minutes or less. It seems like most who arrive early to RSR only ride once and then head out to other attractions. Recently when we have joined the non-EE stampede there have been EE guests leaving the attraction (after riding) when we arrived at the queue. Last time we rode GotG the cast member that walked our group down from the rope drop area routed us through most of the outdoor queue and the ride was slow to load so we only rode it once before heading to RSR. If RSR standby is a priority, I would plan on only riding GotG once. We have older kids so if we don’t beat the non-EE crowd to RSR, we just ride single rider.