Kinda late to the game here but we have been building our own small portable oasts for the past 15 years. We just can't give up the room to make a permanent oast house. These units are automated or manually operated. We use a variety of electric heating elements with simple controls and exhaust...
Like previously stated, where you are located is just not a good climate for growing most strains of hops.
A long cold winter does wonders for a hop plant if it is properly maintained. You typically don't hear a lot about the long deep freeze winters of NC! Lol!
Now with that being said...