That is really hard and it’s lovely that your family are thinking so much about it too.
Fir yourself, knowing it will be different and allowing yourself to feel that but also wanting to pay tribute to your DH’s love of the season and elements that you like yourself, could you take some time in the next few weeks to sit quietly with a coffee and a pen/paper to write down what you both loved about the season - the decorations, the food, the events, the feelings, church services or music, presents, whatever it is. Be as specific as you can.
Then think about what elements of those you want to continue, even in the smallest way, this year. Next year might be different and you might go bigger. But, say DH used to string hundreds of lights outside - is there a favourite bush that you could wrap this year? Or if the house was decorated to look like Santa’s grotto, is there a favourite single element (the crib in the hall, a particular nutcracker on the mantle, a set of festive towels in the kitchen), that you would like to put out this year without doing the whole lot.
Or is there anything you would like to do that is different to mark the season - maybe having a long-lasting candle lighting in a candle-safe holder. Or making the effort to have the fire lit in the evenings but not watching the jolly programmes, but have a stack of favourite dvds or a book you’ve wanted to read to enjoy it by.
Or planning to have a constant supply of mince pies from a local bakery because you aren’t baking your own - but want to enjoy quiet coffees with your visitors still.
And, if it is not too much, it could be nice to find a lovely picture of DH enjoying a past Christmas that you can put in a frame - a happy memory to turn to in the sad days.
That may not be the clearest explanation - but it’s about thinking of the pieces that are most meaningful to you and how to make them still happen but in a way that is not too difficult this year. And allows you to honour your DH’s love (and yours) of the season without it being too distressing for you at the same time.