Paula:
At Disney, you pay for proximity. The resorts that are closer to the parks (where you can walk or ride the monorail or a boat to a park) are going to be more expensive than those where you'll have to take a bus. However, you have a few options open to you that give you proximity without the higher price tag:
Wilderness Lodge: This would be my #1 choice for your sons' 5th birthday. A "semi-deluxe," it provides boat transportation to Magic Kingdom. The stories-tall lobby of the resort with large fireplace and overstuffed chairs will be decorated for a rustic Christmas for your trip, and the room décor appeals to any child. It's a favorite of families.
Fort Wilderness Cabins: When my children were your sons' age, they needed space to run around and be boys. The cabins not only provide indoor "space" with a large living area and full-size kitchen but also a deck and outside fresh air that gives you a break from the parks. It's like a vacation within your vacation. The cost of the cabin can be offset by its kitchen and your ability to cook your own meals. If you fly in from Nebraska, you can order groceries online for delivery from Garden Grocer. Again, you can take its boat to the Magic Kingdom.
The Swan & Dolphin hotels: Located near the Boardwalk, these two hotels are on Disney property but not run by Disney, however, the ability to walk to both Epcot and Disney's Hollywood Studios--or take a boat to either--allows you to feel like you are paying twice as much for the proximity. Keep in mind that you cannot have package delivery or the Disney Dining Plan when you stay here, but the fountain in the lobby of the Dolphin hotel can be as intriguing to a 5-year-old as other amenities in more expensive hotels on property.
Wishing y'all a magical vacation!
Whitney