I've done similar many times over the years, the last being in Jan of this year, most of the driving in snow, but only approximately 600 of those miles were towing a 5er. How I always do it, especially when I would travel with the wife and kids is leave way early in the morning the first day, generally around 1am. I'm used to long days so 16 or so driving hours is easy, and the miles you sneak in with the wife and kids sleeping result in the best time to distance portions of the trip for me. Personally, I try not to sustain a 16 hour day pace for more than a day, so I try to keep the following days down to 500 miles or less for a couple days, then sneak in a down day, or significantly shorter days so you don't burn out.
