I have been through this, with chain smoking in-laws!
Best advice is this:
Don't do everything.
Make your own private space of your bedroom.
Give positive feedback to your mother in laws negative remarks.
Examples: Give everyone a spot for their wet towels, ask them to please hang them up and use them the whole week- bedding should be used for the whole week also.
Kids should be picking up their own things and making their own beds by now.
When you get up, make your bed, straighten up your room and bathroom. When you need quiet time, just tell the family you are going to lie down awhile. You can do this in the afternoon and then an early bedtime- like when your kids go to bed, you retire to your room- read, watch TV, get ready for bed. That way you can relax.
When you are cooking, cleaning up, ask for help. "Sweetie, would you please wash up these pans?", "Mom, would you mind making the salad for tonight?"
The kids can set the table and clear the table.
If you ask them not to stay a full week, you will be the bad guy. Even if your husband asks them, they will blame you, so forget that.
Your mother in law is getting older and with age comes a little depression. She may feel a little jealous at your youthfulness and energy. THis is normal and she will adjust as time goes on. Also, menopause is a very difficult time for women, so that may be a factor for her.
In some cases, you should just take the attitude of "can't beat them, join them". This is your husband's family, you love your husband, so you have to put up with them and they must have some good qualities.
So, if they are lazy, you can try to be lazy for one week. Just put your feet up and do as they are doing. Get some good magazines to distract you. Let some things go for one week- like the bathrooms- just get some disinfect wipes, so that if you can't stand it, wipe up quickly when you are in there.
I have a feeling from your note that you are harboring a little resentment for your husband, since it is his family and he does not help as much as you would like. Ask him for help when needed. Men don't know and telling him later won't help. Ask at the time of need. If stressed, maybe in the middle of the week, you and hubby and go out and see a movie and leave the kids with grandparents.
Remember: Nothing lasts forever.
You can clean up the next week. And cherish the memories of a happy time with all the family over Christmas!