Hmmm. That's a good question! Do you have a place such as a well-lit garage where you could winter them, and try planting them in the spring when they're more established? I wish I had some experience with this myself. Good luck :)

Here is a link that might be useful: Plant Avenue

I'd keep them outside in a protected area. An unheated garage can work, but can also cause problems, especially on hotter days.

Easy enough. I realized I can put them in my raised vegetable bed and enclose it. And they're zone 4 plants.

I actually did that last year with a young Syringa offshoot from my neighbor's plant. Should work...thanks for helping me think it through.