Personally, I consider cold smoking to be bellow 120F, and if I could do it consistently , I'd prefer it to be between 40F and 80F. I did some bacon this weekend, I was running my PG500 between 120F and 140F for about 8 hours... I was able to do this because it was about 30F outside. In summer , running this same feed rate I'd be lucky if I could run at 180F, probably would push up toward 200F ( which is too hot for me if I wanted to do bacon or jerky ). If I run it lower feed rate, the smoke can get a bit dank, and may not produce food that I would enjoy that much...
So, anyway... if I could reliably smoke with good smoke between 40F and 170F, I'd find something to smoke at least once a month... If I could do 120F to 170F reliably even in summer months with little effort , I'd be a happy camper. However, the smoke would have to be of high quality... I don't like food that tastes like a ash tray right after you take it off the smoker.
I've never been able to get really good smoke down into what I consider to be real cold smoking temperatures( realistically around 60F to maybe 80F )... I tried smoke tubes with just the fan on, didn't work well for me... The only thing I would smoke at these temperatures would be like bacon, maybe ham if I ever got the urge to make my own ham... and possibly some sort of sausage, but I have yet to make my own sausage of this type.
I'm not a big fan of smoke cheese, so I have no interest in that... I love smoked fish, ( whitefish and similar )... but I'd have to really go to school on how to do a smoked fish of that sort.