Paul, there really is no 'ideal' temp for dough. The 'ideal' temp is whatever temperature ferments the dough properly within the time frame you're attempting to ferment it for your particular environment.
These factors can all affect fermentation:
Water temp
Flour temp (ambient temp, unless you refrigerate it)
Flour protein content/particle size/damaged starch content/enzyme content/water content (every flour will ferment a little differently)
Hydration
Insulating properties of the container
Refrigerator temp
Kneading time
Kneading equipment (hand vs. mixer)
Time (in or out of fridge)
The style of pizza being made
Sticking to the same brand of flour helps, but bear in mind, even the same brand will vary from bag to bag, so don't assume the new bag will bake up exactly like the old one.
Hydration is not a huge factor, imo, but it's still best to stick within a +/- 3% range
The fridge temp is what it is. Sure, you can invest in a fridge thermometer and test it, but for most people, it's fairly constant.
Mixers, as you know, generate heat. They also tend to knead more aggressively than hand kneading. Cold fermentation develops a lot of gluten in itself, so if you cold ferment your dough, I recommend scaling back on the kneading dramatically. If it's smooth before going into the fridge, you're kneading it too much. It should look like cottage cheese. In order to remove the gluten development variable as much as possible from the equation, I try to always knead the dough with the same intensity for the same amount of time. I also mix the dough/make the balls in approximately the same time frame (delays will allow the dough to hydrate and thus mess with the gluten content).
I use bottled water or tap that's been boiled and then cooled (my tap is basically pool water, it's so chlorinated), which I store at ambient temp. Cooling water or warming it is a hassle, so I use it right out of the bottle. I do make a note of the ambient temp, though, for reference. I also knead by hand so the dough temp is pretty much ambient temp. As ambient temp goes up, I adjust my yeast content downwards (and vice versa).
It's a little bass ackwards, but you really have to learn to recognize properly fermented dough before you can trace your steps to see how exactly you achieved it. It's important to document everything and mitigate as many variables as possible, but, until you know exactly what to recognize, it's impossible to avoid at least some trial and error.
And, as far as not exceeding 80 deg dough... I'm not sure it's really that cut and dry. In theory, one could have a minimal yeast, same day emergency dough that's started at a higher temp to encourage enzymatic activity (while still not ballooning up too much). One important thing to remember is that water takes a lot of energy to heat/cool and that fermentation creates heat on it's own. The warmer the dough, the more yeast activity, the more fermentation heat that's going be generated, which, in turn, will affect the time it takes to chill in the fridge. Refrigerators take a long time to chill foods, especially foods that are generating heat as they chill.
