We also had a good experience with Wally, who was probably only 5 or 6 weeks old when we got him (instead of the 7-8 we'd been told).

We always gave him access to a pee pad, and I think because he was so soon after the whelping box he seemed to know to go there and the only real accidents we had were when his aim was off, or I picked it up and didn't put another down fast enough. However, we took him outside diligently (as soon as he woke up, before and after meals, every hour otherwise) and praised a lot for doing stuff outside. Eventually, he just stopped using the pee pad of his own accord.