Decorating biscuits, co op do kits or bake sme simple ones and let them go mad with icing on top.
Christmas disco, just Christmas lights and songs, Dh and toddler can dance, you can rest and watch them!
Make an igloo, a den of blankets with a white sheet thrown on top, tuck up with some Christmas stories inside.
Could you use Amazon to order some christmas/fun bath bits, crazy foam, colour changing bubble bath, my ds' loved baths when they were toddlers.
My ds also use to play for longer with toys I had set up a bit, made the train track or set the animals up in the farm etc, so maybe some mornings during the festive period dh could take them out for a walk whilst you set up some play situations, do you have an christmas small world sets?
Drives to see Christmas lights early evening.
Zoom calls with family members.