What I did for Gen Con 2011 before I got my tablet last summer, was lug my giant box if books to my hotel room. I also new what I was GMing and playing each day, and with an hour between 2nd and 3rd slots, I could easily bring only what I needed. Yes it often was a heavy backpack. But easier than carrying my entire collection around.
I also remember Gen Con's and Origins from 2002 to 2004, where PDFs were not an option for Living whatever, and folks would have time of rolling carts and whatnot.
Where there is a will there is a way.
Just know you need your sources in some capacity is all.