Oh Karen, you know how loved you are from afar. You have been given some thoughtful understanding and advice which I couldn't begin to match, so I'll just add my two cents.

Everyones situation is different so you have to try to find what is going to work for you. You will never be able to replicate what you had with your folks. It has made for wonderful memories which you should cherish, but maybe new traditions and activities can add something to the holidays which will help them to be happy again, if in a different way. Like new clothes and redecorating, change can make life purposeful. You have a zest for people and life. Dig deep to access that innovative and social part of your personality and set out on your journey.

That said, I know how hard it is. It's much easier to say what you think others can do than it is to gear up oneself. But you, my dear, I have so much faith in what you can formulate, even it is just one or two new activities to look forward to and implement.