Thanks for the input everyone, it really helped out. Completed my first all grain batch last weekend and it's been fermenting well for the last week. Brewed up a Breckenridge Christmas Ale clone, so larger gain bill than a normal 3 gallon batch. Heated my strike water to 168 and poured it into the cooler and let it sit for about 5 minutes to heat up the cooler. Got to a mash temp of 154 after stirring in the grains and only lost 2-3 degrees during the hour mash. I also covered up the cooler with an old comforter to help keep the heat in. Did the vorlauf and drained into the brew pot. Batch sparged w/ 175 degree water, vorlauf, and completed runoff which got me to just under 4.5 gallons of wort. At 1.074, I just missed my OG of 1.078, but I can live with that.