They are about 6" long, can I cut them in half then? No greenery yet, using the bag method.
You can do two things-
1)Cut in half and buried horizontally just below the surface
2)Cut in half and bury vertically. Make sure at least 1 if not 2 nodes are exposed above surface so buds can form.
You can pot it like normal and the roots above surface will air prune away.
I have had the same problem but my cutting was about 10 inches long, so I had a better size-3 inches might be a little tight. Doesn't mean it won't work.
You have roots so the most important thing has been established