Mick, having gone back to my complete solo Holborne, I found the wonderful (and very tricky!) As It Fell On A Holy Eve, too, as well as The New Year's Gift. I have picked out the bandora accompaniment consort part of Heigh Ho Holiday (the rest of the consort parts are missing) and worked it up into a 4 course guitar arrangement, as it fits so well on there.
And Bonny Sweet Robin - why didn't I think of that! In the duo, we've had great fun trying to find the most tenuous and improbable connections to winter / Christmas - I think Mris Winter's Jump and Bonny Sweet Robin must come pretty near the top for tenuousness - we'll take them!
I love Thomas Campion's songs and am planning to sing Never Weather Beaten Sail (not Christmassy or wintery, but beautiful and with a religious theme). Why am I not familiar with Now Winters Nights? Thank you, Mick - it's beautiful and the words are exactly right for the programme. I know I said we didn't want more songs, but I'll certainly make an exception here.
leeneia, In the fields of frost and snow is discussed above. I found the words to it in D'Urfey's Pills - great fun - contemplating whether to do this as a Playford tune or an audience singalong.
Thank you again for your time, generosity and suggestions. It is very much appreciated. If any of you are in the area and can come to The Night Watch Winter Warmer, I do hope you will introduce yourselves.