Greenhouse Fruiting Trees

Does anyone have experience using their greenhouse/ climate battery to grow fruit trees? While some fruit trees and many berries will survive our winter temps, our summer nights are almost always less than 50 F and we have less than 90 days that are frost free. Due to this, very few things have time to fruit.

I've read Forest Garden Greenhouse and seen the citrus greenhouse in Nebraska, however I am not interested in growing tropical fruits and am looking for advice from someone in a similar climate to mine. The plan is to grow trees and berries that would typically withstand our winter and maybe one zone higher, using the greenhouse to allow them to wake up and begin to grow in April, not June, so they would have time to produce. I had almost decided not to use a climate battery, it's just so hard for my brain to wrap around it working in -30 (our spring temps can still drop that low), however after conversing with another poster on this forum, it sounds like it will add some benefit.

I feel like in theory, it should work fine.  I'm just curious if anyone has done something similar with fruit trees and if so what have the problems been that I can avoid and what was successful?

As well, has anyone used phase change materials on their insulated walls and if so what has your experience been?

Thanks!

A sun-well or a fruit wall might be worth a look.
https://worldsensorium.com/fruit-walls-urban-farming-in-the-1600s/

At Wheaton Labs in Montana they were trying a sun scope back in 2016:



https://permies.com/t/berms#513670

Paul said, "That topmost video shows the rhubarb and apple tree at 3:43.   Here is a more recent pic taken in late september 2018:

Alfalfa is a nitrogen fixer with a deep tap root.  I think this picture is evidence of the alfalfa finding water and sharing it with the apple tree and the rhubarb.  

https://permies.com/t/berms#1018657