How do I tell my in-laws that we will be hosting Christmas Eve dinners in our home from now on?

My grandmother usually cooks Christmas Eve dinner, and my husband’s family does it as a collective thing (they are Italian, so a few different people in the family cook a seafood dish and it is usually held at my husband’s grandparents’ home.)
Last year, my grandmother decided that a traditional Ukrainian Christmas Eve meal was too difficult for her, as she is getting up there in age, and opted not to cook. This year she has decided that she won’t be cooking for that holiday anymore. My family and I have decided that I will take over.

All in all, I’m more than happy about taking over, and I’m greatly looking forward to not having to run from house to house (like we do for most holidays.) However, I’m not sure how to tell my mother-in-law, who I suspect will be very displeased that her son and her grandchildren won’t be coming over for Christmas Eve. We will see them on Christmas day, though.

Also, my in-laws (especially my mother-in-law) never come to our home. I think they have been here 4 or 5 times in the almost 7 years we’ve lived here, and they may have come in the house twice. I feel like I should extend an invitation for them to join us, but realistically I know that with them cooking, and their resistance to visiting us at our house, they won’t actually come. I should offer anyhow, though, right?

I’m not asking for lies, obviously. I just need help with the best way to word my email to her.