Best way to handle out of season planting?

I have access to a nursery that sells end of season (out of season) stock at 90 - 99 % off their retail value.  I have some items in various stages of growth and I'm wondering what others would do in my situation.  Here are my options:

Here's a sample of what I have right now:

Early Amethyst start (6 inch pot) with tender leaves  (out of all of the plants, this one must not die.)  
bareroot hibiscus (probably 2-3 years old)
hibiscus start (6 in pot) with tender leaves
bareroot peony (Gardenia) that has started to break dormancy
bareroot iris (Shaker's prayer)
fritillaria bulb

Temps. are forecasted to be mostly in the high to low 40's (with some high to low 50's) during the day and low 30's to high 20's at night for the next 15 days.  Precipitation in the form of rain or snow every 3-4 days on average.  Humidity mainly mid to low 70's and high 60's.

Here are my options:

1. Potted and placed in outdoor unheated greenhouse made from 16mm twin wall polycarbanate (temps. will be 40-60 degrees in there for at least the next 2-3 weeks).  I also have the ability to add another layer of protection by putting them in a low tunnel made from the same materials that can be further insulated with wood chip mulch. I don't believe that the temps would fall below 25-30 degrees for the entire winter in that setting.  
2. Outdoor unheated hoop house (4 mil greenhouse plastic). Can be potted or put in ground. Poly low tunnel with mulch can also be used in here.  Not sure of temps with this option.  
3. Outdoor wood chip based nursery, plants can go in ground, or in pot and be covered with wood chips.  I do not believe that the ground freezes in this area due to the amount of wood chips that are in the area.  Poly low tunnel with mulch can also be used in this setting.
4. Potted and put in heated indoor grow room with artificial lighting (last resort, don't want to use the space if not needed).  Temps. are usually between 68 and 75 in this room.  

Any other options that you all can think of?  What do you all think is the best option?

T.J. Stewart wrote:

Early Amethyst start (6 inch pot) with tender leaves  (out of all of the plants, this one must not die.)  
bareroot hibiscus (probably 2-3 years old)
hibiscus start (6 in pot) with tender leaves
bareroot peony (Gardenia) that has started to break dormancy
bareroot iris (Shaker's prayer)
fritillaria bulb

That's a nice connection with the nursery! I like to collect out of season, clearance plants as well.

My experience with iris and peony when I lived in zone 4 leads me to believe they would be fine planted outside anywhere.

A friend had a hibiscus growing right next to her house in zone 4, but I know there many varieties each with their own hardiness...
Do you know what conditions they were grown in at the nursery? If the 2-3 year olds were grown outside, meaning they have survived your winters already, then they should be fine outside as well. If the variety is listed on the plants, that makes it easier to find out their hardiness.

If it was me, I would put the 6 inch hibiscus in shelter for this winter as it still has leaves. But I don't have much experience or success with hibiscus...

I have no experience with fritillaria, sorry.

For the early amethyst, if it must not die, then I would put it in the warmest place so you're not stressed about it. I have seen them growing outside in peoples gardens here in zone 8ish.

When I get plants that are new to me, I err on the side of caution until they produce seeds or cuttings. Then I experiment with the offspring.

Good luck!

Thanks for your response @Amy.  I actually decided yesterday (before I read your post) to just plant everything outside directly in the ground.  I am considering it an experiment.  I planted bare root peonies last year in December and they did fine, so I decided that it should be fine again this year.  I checked the Amethyst again and I felt that it was mature enough to handle the weather.  I'll try to remember to come back in the spring and update if I can.  :)