We actually own II and DVC and purchased DVC after staying at OKW through II last May (2004) - DH was online one very late night and was idly searching for vacation ideas and stumbled upon a 2br OKW and booked it without even asking me - it is that rare. But it IS possible. However, to be on the safe side I can recommend a few places we have stayed pre-DVC through II. The Blue Tree Inn Resort is close to the Crossroads at Lake Buena Vista, are almost always available and had very nice accomodations. We also stayed at Celebrity Suite and Spas for a few days and the three room condo was huge and very nice - located right off of 1-192 and very close to SuperTarget (yayy!). However, the closest you can get to a WDW experience without WDW property is definitely the Sheraton Vistana which is fantastic and usually available. If you have any questions about II, feel free to PM us at any time - we've had it for several years and while we love DVC even more, we wouldn't get rid of II.
Hope this helps!
Jennifer