Winston's mom,
I have had several friends who've used the playpen with much success. They had a pee pad, and a place for their puppy to sleep at night there.
I'm not sure that it will help you with potty training, in that you are not training him to hold it for long periods BUT you need your sleep, and since you aren't having much success with the crate, the play pen is definitely worth a try.
Be aware - he still might whine and cry for your attention.