:Although my experience is short, my success in cheese smoking seems really good...to me, anyway . I have similar experiences. Above 50, I can hit 85 in the smoker, too high. Below 40 however, it can't get it over 65 and mostly 55. My whiskey barrel smoker is on the north side of the garage where I do much of my outdoor work. It is always very cold there with so little sunlight there until near sunset but it's too late then, you're usually frozen by then. I have a bi-metal thermometer In a silicone bung hole plug but it's "sweet spot" is more towards 200-250 and it's accuracy is off about 20 degrees at room temp. I am using the maverick dual probe which seems to be darn close to actual temps so I keep one probe on each rack.
I have had anyone in the house immediately notice when I bring a rack of cheese in from the smoker and that's after maybe 20 minutes hanging in the garage. My color has been intense you can see the crosshatch clearly from the rack on the cheeses' surface. At the highest temps I've had, about 85, one of the cheddars' started to get oily. I let it dry and vac sealed it a day later. It looked great but remains to be tasted. I wait for temps below 50 and just go ahead and do it. That has not been a problem in the last 3 weeks.
As mentioned, it's a lot of fun and I'm always out there doing something. It mind mellowing, to watch the smoke rolling out of the short stack. I've done over 10 lbs at a time and just 1 lb alone. Always feel like I've accomplished something.
Enjoy, if you really get into smoking these cheeses, keep a close watch for local supermarket sales. I've run into a few that built my inventories well.