I am a new beekeeper from Alberta. Canada. We extracted honey from hive two weeks ago and had a nice production of 15 quarts. 2 weeks later Peeked through end door and
Could see the frames were capped and pulled a few to get a better look and they were completely capped with wax. Set up to extract honey and only had about one cup each. Very disappointed so after draining all the frames I removed them and
With my capping removal tool I scraped a quite thick layer of wax off and returned them to the hive. There was no way to know how much honey was in the flow frames unless maybe weigh them. I don’t have a moisture meter but the honey flowed like water so I think it is too high in moiture so I refrigerated it am wonderirig if I should feed some of it back to the bees? Removed from 12 frames in two hives so have about 5 quarts.
How much space do you have in your brood boxes? Hopefully you are running at least double deeps for brood, given your northern location… 
If there is empty space for honey stores, by all means feed it back to the bees.
The other option is to get a refractometer (moisture meter). You can find them for under $40 on Amazon and eBay. I bought this one, and it is easy to use and works well:
I had to ask the seller to ship the dioptric oil and reference block separately, because they were missing from the original kit, but otherwise it was a very good purchase.
If you are feeding back to the bees put it in a rapid feeder on the top.
OR you could jar and freeze it, taking a jar out as you need to use it for yourself
Use medicinal liquid paraffin, this should calibrate to 24.5%
I added a 3 supper on top of my flow hive. A10 frame one. Screwed some wood strips on each side to close it off as I could not get the narrower one locally and I was worried my Beas might swarm and also needed extras to winter. They have almost filled them so I hope I have enough for wintering them. I will buy a refractometer to check the honey. I will keep it refrigerated for now. I was wondering if I should move the extra supper under the stack? Reading lots on the forum and learning lots.
My bees always do better when I add new brood boxes underneath the existing boxes. In your case, if your new box is 10-frame and your bottom board is 8-frame, you may just want to leave it on top.
I don’t recommend having supper in a bee hive - your tongue might get stung! 