I haven't read all the posts, but I did see the bit about your DC wanting to do stockings at home.
It sounds very feasible. It gives you all what you want - waking at home, seeing family, other family hosting.
It is a decent drive to contemplate, any day. But I presume you are used to it if going to family. Having DVDs for DCs is a good idea, and making it fun. Hot choc (snowman soups?!), and a "car picnic" with some nice treats (not all sugary sweets - are there posh sausage rolls they like, or particular biscuits or fruit, and a nice drink as well as plenty of water?) would be good, although ration it (have plenty in boot in case of troubles as probably few places open, but just have enough to stave off starvation and boredom in car, not to spoil the turkey dinner).
Remind yourself in advance of the usual car games (I spy, How long is a mile/next junction etc, how many red/green/blue cars, Car bingo (but will have fewer trucks and buses than normal) etc). And if you have any travel games for in the car (connect 4, hungry hippos etc - Ker plunk is not so great!!) or a pack of cards.
Have a carol singing contest, or nice Christmassy CDs to play.
Check if family who are hosting want you to bring something as you won't be around for the preparations. (And be prepared to be chief washer-uppers after).
But it does also mean that DCs can decide on a few new things to bring (leave a space in the pre-packed car) and may have things useful to play with en route (does Santa bring DVDs to your house - that he might have a new one for the car this year?!).
And it also means that you can enjoy the dinner on arrival, and sit around after some wine etc, without facing driving home again.
We keep threatening to do this ourselves (2.5 hours drive) - but keep renting a house between both sets of parents instead (20 mins apart) to get our bit of peace and quiet. And alternating with Christmases of just ourselves (DH, DD and I) at home - some one of these years, one side of the family might actually agree to travel to us. But Christmas at home is nice too, stockings, nice brekkie, Christmas morning mass, visiting locally and a walk on the local pier as well, getting home while still bright (a treat for us at that time of year), lighting the wood stove and checking turkey (I set up the timer to get it started in case we get delayed out), and relaxing with some wine while it finishes and we open presents together.
So while mostly I am saying yes to driving on the day, don't knock the idea of a quieter family day either. It can be really nice and relaxed, and doesn't need to be flat at all.