Yes, the chance for extra renewal would be great. Our librarians do this for us sometimes because they know us, but it would be wonderful to have it as an official policy.
Our sweet library is 60 books per member, DH and I go together so that makes 120 and we can renew twice and that makes it 6 weeks total. We go together or alone and our library has a large play area, lots of toys, benches, and coloring tables. I wince when I read up on other libraries (home shopping). I love our library sooo much. It is by far one of the most amazing places. I feel so much that 6 weeks is a great time period. I love reading books too but I can't cram them. The toddlers get so many books, it is really like the tv. We do lots of learning with Freddy on nature and big questions like "What is a calender?" I bring home books on animals. I also get some rotten eggs, about 5 not so cool books. I don't live at the library, but I take them back no matter what - just for that good karma shelf status. When all it is is a book drop near the grocery center, it is no pressure to take back the "finished ones." I looooveee libraries!!!
6 weeks!!! I totally vote that!
(BTW, books are like TV in this house. I bring 5 out with me when we go driving to places.. I am one of the few lucky moms that has a driver and can read books on the way to DC though. I wish more for homeschooling moms that we had a huge huge huge stock of dvds for this reason alone - car trips.)