Here's a quick pic of our cardboard gate... it's not pretty, it's a pain to step over, but it's easy to expand your pup's area really really slowly. We expanded Nikko's area by about 6sq ft at a time. Just remember that he can never be left unsupervised in his gated area - if he's in there, you're watching him. If you're not watching him, he's gotta be on your lap or in his crate.
From when we got him at 3 months old, Nikko had a full two months of gradually diminishing accidents, with small success streaks then potty breakdowns, and back again. A horrible yo-yo of frustration for him and us. Two months of obsessively watching him, getting tiny pees inside the house even after he had just peed outside, and all those other problems with housebreaking... definitely some of the longest couple months of my life! But then at about five months old, with us constantly and carefully watching him, he hit the beginning of his current over a month long accident-free streak. Recenly now, and with the nice weather we've been having, we've begun just leaving the door open during the day. He stalks in and out whenever he wants, and even happily deposits his pee and poop outdoors when we aren't paying attention! It is
awesome!
Here's the pic of our cheapie gating system:
CardboardBoxGating.jpg