[MamaS]

I totally agree. Travel for Thanksgiving if you must, but kids should be at their homes for Christmas (so Santa can find them)!
When you are feeling better, send one more email to your aunt and uncle and tell them how you felt and why you will no longer be visiting their home. If they wanted an "adults only" Christmas, that is their right, but they should not try to have an "adults only" Christmas by putting the kids in the corner -- or in the kitchen. They deserve to know what they lost and why they lost it and telling them might make you feel better.
Sorry about the pneumonia -- I had strep throat all through Christmas, so I know about the "dead on your feet" feeling.