I think this could be possible, depending upon the ages of the kids. As we've already discussed, if you have kids 3-9 years old, then the DP is more than likely going to be better, especially the DxDP. You have to factor in that savings into the mix as well.
I will admit though, that the regular DP since they changed it by removing tips and appetizers, isn't as much of a savings as it once was, but it still is a savings.
We have just done extensive spreadsheets comparing DP, combo of DP & DxDP, TIW and DxDP, and for us as 2 adults, 6 year old and 2 year old, the DxDP is the way to go. The TIW card, actually will cost us several hundred dollars more over the DxDP and that is because snacks aren't covered, as well as the fact that we would need to purchase kids' meals for our very hungry toddler, but with DxDP, we can use the appetizers for that.
It really does depend upon the situation, but for us, we only order what we can eat, and so we only compare apples to apples, so in our comparisons where the TIW card would cost quite a bit more, that was only ordering base meals, no beverages, 1 kids' meal and 1 appetizer or additional kids' meal for the baby, and the TIW card still comes out to be a lot higher for our family situation (we also do not drink alcohol, so we wouldn't be using if for that either).
Good luck to all - it seems so many DISers don't care for the Dining Plans, and always seem to favour the TIW (we've used it 2x now), and in our opinion, it's not that simple.
The good thing is that Disney offers so many dining choices now, that there is bound to be something to fit most family's needs.
Tiger