I definetly think you should stay in Disney rather than out.. Don't get me wrong, there are great places outside Disney but usually the nicer places outside of Disney are best for bigger groups. Also, nobody has transportation to Disney as good as Disneys. From what I've experinced staying at multiple off-site resorts is that there is a charge, and its not as easy to get there and back. Meaning, usually you need to request and call, and the buses don't run as frequently. Disney's buses run about every 15-20 minutes. During the time you are going which is off season, the transportation will be a breeze in Disney and I think it will be even more hard when staying offsite.
As for resorts, I would say my favorirte Value resort is Pop Centuary. They have a very nice atmosphere, you don't really have to walk to far to get anywhere, and they have the best food court in my opinion! You won't be dissapointed. However, for a couple such as yourselves be aware that there are a lot of little kids running around, and there it no hot tub. Hopefully, you wouldn't be spending that much time at the resort, and you'd take advantage of everything WDW has to offer. Just guessing on top of my head the rate could be from maybe 85-120 a night. I haven't ever stayed in late January but I have always been offered additional night add ons for low rates because right after the first week in January it is one of the quitest times of the year.
My favorite Moderate resort as said above is Port Orleans Riverside. I love the theme of this resort, and it isn't as crowded and hectic as a Value and I have always found it very tranquil and relaxing. I think for a couple this would be perfect. It also has a very nice pool, with a hottub, and a great good court. Unlike the Value resorts, there is another mean of transportation besides the buses. This resort offers a boat (or water taxi as they call it) to Downtown Disney. The rate here, I'm unsure of because the last time I actually stayed at this resort it was called Dixie Landing. I'm going to take a guess and say it could be anywhere from 150-220.
As for a close offsite place, I suggest Orange Lake Country Club. I love this resort. It is HUGE and there is so much to do. They have 3 large pools and many quite pools. They also offer studios, 1 bdr, 2bdrs and 3bdrs. While I love this resort, I really think you should stay in Disney! Off season is the best!