I delayed my trip to the middle of May due to reports of lingering snow and am heading out NOBO from Pine in mid May with the goal of hiking to the Grand Canyon South Rim. From my research, it seems like low temps are likely to be in the mid 30s to low 40s depending on elevation along that section for that time of year. Does this seem about right? I'm debating whether to take my 10F ZPacks quilt-bag or my EE 30F quilt. The weight difference is only around 7 ounces but with some longer water carries, I am trying to shave base weight where I can.