Hey thanks all for the recommendations!
Especially this thoughtful explanation:
I tend to do everything I can to make sure the yeast complete the full cycle of fermentation. If you halt yeast activity early, whether on purpose or by accident, you risk fermentation off-flavors such as butter (diacetyl) or astringent green apple (acetylaldehyde). This is especially true in a lager fermentation.
I'd rather have a beer that is clean but too dry than one that has the proper finishing gravity but is flawed by one of the above flavors.
Wish I had read it before I acted. That will teach me to ask questions on the weekend.
I went ahead and transferred to secondary glass and set it outside on the porch for the night.
23 degrees will drop some yeasties.
Not too worried about stopping fermentation at this point,
airlock activity has all but ceased, but hoping I have caused no off flavors.
I guess I do not fully understand the yeast "clean up after themselves" thing.
There is a gorgeous white yeast cake at the bottom of that secondary vessel now.
Are those yeasties somehow incapable of cleaning up their mess?