I have driven twice now and am driving again at Christmas, the journey is as easy or difficult as you want it to be. Our itinary is:
5am leave home in hull over the humber bridge, stop half way at peterbrough service station and arrive in dover around lunchtime, we book the premier inn for a stop off then get the ferry at 3.20am

then at the other side drive straight through to Disney.
We make a pack up the night before for breakfast/dinner for the journey. Have tea at the premier inn, eat whatever is left of the pack up on the ferry early the next morning.
The Cost is around £50.00 for night in hotel. Tolls for the bridges £4.50, up to £100 for tea, £100.00 ferry return (last october price), and we were staying at Davy Crockett so budgeted for £250 for petrol for driving from hull to dover, then calais to disney, and driving to and from the park each day and then return. oh and 40 euros for the tolls both way
I love the freedom of being able to stop when and where I like.
Hope this helps