As far as how much leveling we really need to do. Back in the mid 70's we got a 25 foot Airstream and were traveling with the WBCCI. We had trailers for years but smaller and easy to level. I talked to a lot of guys we were traveling with and they all said there were three rules.. You need to be comfortable inside. A coke or beer can should not fall off the table. And always be sure the head of you bed is higher than the foot.  For traveling we go by those rules aand spend little time leveling. Our rig sets 2 inches low in the front and the head of our beds is to the rear. When staying in a site long term we do spend time getting it better. Also in the last 30+ years we have not had any problems with the fridge except if you open the door ans some thing falls out... 
As the OP said 5 inches is alot. But perhaps you may be comfortable with less.. But do need to carry things so you can get it better.. And there are some sites you just need to pass on.. Like one we came across last fall in Lost Lake State Park in Oregon.. I would have needed 18 inches to get into the ball park.