The cheapest DVC 2BR nights at OKW will still be 22 points, which is likely to cost $220 per night, Sun-Thurs nights. You'd have to make other plans for Fri/Sat nights, as those would cost 54 points each, or $540 per night.
The cheapest onsite options to accommodate a family of 5 (or 6) are, in order:
1. Campsite
2. Two rooms at All Stars
3. Wilderness Cabin at the campground
4. Contemporary garden wing (if you'll only have 5, not 6)
5. Two rooms at a Moderate resort, including the junior suite at CSR (really just 2 connecting rooms at double the price of 1 room).
Everything else goes up from there in price. If you'll have 6 people, plan to pay those prices or stay offsite. January is usually quiet, with good deals and discounts out there. Look for one.
Consider staying in 2 rooms at a hotel in DTD, like the Courtyard by Marriott, which offer regular bus shuttles to the parks. They have had rooms as low as $20-$39 per night during slower periods. Other offsite options abound.
If you will have your own transportation, many offsite resorts are much nicer than All Stars, and offer other benefits at the same price (ex., full 2BR condos with jacuzzi tubs, washer/dryer, etc. or suites with free breakfasts). But you'd need your own transportation to the parks. HTH!
