As determined as you are, and based on my own experience, I'd give it a try, as far as the sunlight is concerned. A Sarah Bernhardt in my garden getting only early morning sunlight, with dappled shade from high oaks the rest of the day, grew and bloomed and was disease-free, but did not bloom as heavily nor increase in size as rapidly as when it was moved to a sunnier location.

What I'm wondering is how you intend to overwinter this plant.

I would start with a tree peony rather than an herbaceous. You will need to provide some protection this winter both arround the pot and plant.

Contrary to what the article states peonies can be quite happy in partial shade. In some areas where the sun is very intense such as in the mountains shade is necessary. Red flowered peony blooms will last longer in partial shade vs full sunlight since the red coloration holds the heat speeding the flower from open to loss of petals.

There are natural dwarf peonies both tree and herbaceous. I have seen a tree peony shown as bonzai but it did not have flowers. Look at Klehm's for rock garden peonies. Alice Harding is a natural dwarf tree peony. Some plants sold as Alice are not. If your Alice grows more than 2 inches a year it is unlikely you have her.

I've read that placing plastic around the pot and stuffing leaves between the two works well for winterizing.

Thank you for your suggestions, everyone I ask says "oh no you can't grow peonies in a container!!" (I'm getting the same answers for hydrangeas - frustrating!!!)

Nothing ventured, nothing gained. You may as well give it a whirl, and report back. Good luck.

Some of the greatest things have come from someone that tried some thing that everyone thought would not work.

Rather than the plastic with leaves try putting in a box with space of about 3-4 inches to each side for stuffing leaves. Unless you buy a potted plant with buds already on it, unlikely any plant purchased now would bloom this year. However it might next year.

It could be placed into the ground any time in the summer once it has established roots or cut it back and placed back in a dark, cold, dry area in September. Although "potted peonies" behave differently than ground planted peonies....it works.

I have had 2 peonies planted in pots for the last 3 years. They are loaded with blooms. I bring them into the garage during the winter and put a little water on them once in a blue moon and take them back out in the spring. They are looking really good this year. They have multiplied a lot and have several big blooms.

Who said you can't grow hydrangeas in a pot? I've had a Nikko in a 24" pot for over 20 years. I bring it in the garage every winter and water it once in a while. I just took it outside last week. It's full of buds right now and will bloom soon.