Not only has babyproofing Nana's basement been a success, but we've also gone an extra step and created a play corner for all the grandkids (Three now, FIVE by Thanksgiving!)
This awesome play space includes a big wooden toybox (the one I used as a kid), a bookshelf full of fun books, a big basket of horses, bins full of blocks, duplos, & little people ("Peoples" as we used to call them), a rocking horse (Grandpa's from when HE was a kid), and nice cushy ottomans (great for standing practice).
This is definitely a Sophie-approved area. She will crawl the entire length of the basement to get to it, and then she'll just hang out for a while.
p.s. This little girl now has SIX teeth. Here she is showing most of them off.