If you want to go 3 or 4 days at a time all you need is two 6v deep cycle batteries with decent AHs, a good charger, and a generator if you want to extend your stay. You don't need solar for 4 days boondocking. I went with Crown, check them out. Get a good charger. Check out backwoods solar for their modified Iota 55amp 15.4v charger. Also get a trimetric to monitor your usage. Update to all LED lighting and a 12v TV and you are set. I go 4 days easy on a single charge but I have my Honda generator to charge back up in 2 hours or less at idle. We watch lots of DVDs, operate our awning, run the heat here and there etc... My resting voltage is 12.8v and I drain it down to 12.2.
PS. Handy Bob is your friend when it comes to batteries, charging and/or solar.
TV: 2012 Ford F350 CC 6.7L 4x4
TT: 2014 Wind River 250RDSW [Dual Crown 6v, Trimetric, Iota 15.4v 55A charger]