I have 2 Vinca plants that have been growing in containers all summer. I'm in zone 6a, and have read that Vinca is perennial for my zone. Here are my questions:

1. Can I transplant them to ground to overwinter?

2. When is the latest I can do that?

3. The plants are bit bushy and gangly. Should I divide and cut back when I put them in the ground?

4. I want to grow Vinca in container again next year. Should I save cuttings or seeds from the current plants?

Thanks very much.