What about...
I love the ideas posted above - I'm going to work them into my plans!
Can you do a 'gift' workshop of sorts - just don't necessarily call it gifts? You'd need to be creative in what you 'make', but at the end of the day, the students could 'take home' what was made in their assembly line. This would be a good lesson on working together.
One idea to 'assemble' would be the ink pens with a topper. You've seen the pens at the Dr.'s office with the HUGE flowers attached - you know, so people won't leave with their pens? What about buying winter/holiday picks at your local craft supply store - like snowmen, poinsettias, just anything that would represent the season - but not the holiday. Then with florist tape, let the students 'wrap' the pick and pen together and 'create' something that they can take home and distribute. OR, if your school has a winter carnival, your class could 'sell' their wares. My son's class finger painted very LARGE pictures last year, hung them in the hall like a gallery and 'sold' them to parents. Of course, we all bought them! Them money went to the PTO fund.
You can also take leftover pumpkins that haven't gone bad and spray paint them white. Then, hot glue them into a snowman, largest on bottom. Let the students decorate the faces, etc. It's a great way to re-use fall pumpkins.