In my view, the best strategy is to plan your pace based on the worst weather you'll see during the race. So, if the race starts at a T+D 100 but ends at a T+D 150, then I personally would plan to run the whole race like it was a T+D 150. All that means is that the beginning will feel far easier, and that's ok. You're saving everything for the much much MUCH harder part when it is a T+D 150.
There isn't one answer. Not everyone responds the same to heat. Some people's personal adjustments in training and in racing are more aggressive than others. So I view the T+D adjustments as a cap of sorts. You can absolutely go slower, but don't try and go faster. I've mapped my personal racing/training data. I track very closely to the curve during training all the way up to T+D 160-170. But races are different. They push the body much much harder than any training run does. So I've found that my T+D adjustment in racing tracks well up to ~135, but after that I need a far far more aggressive slowing in pace. After years of experience, I've learned that I really have to throw out many, if not all, pace based goals once the T+D gets over 135. My body just can't handle anything close to what I'm capable of fitness wise under those conditions. So if it gets super hot for a race, it's time to put pace goals on the back burner and just coast as slowly and comfortably through the race as I can be. Find a different way to enjoy the race.
My 10k costume was almost “Lisa Frank Minnie,” which obviously I made up, and because of that couldn’t quite get as excited about as an existing character (for a race I’ll be running in the dark, who would see my patterned nail wraps?!) 
