Fracked up brew session/fermentation - how to calculate priming sugar?

Hi-

Ever have one of those brew sessions where everything goes sideways? Brewed an oatmeal stout last week. Digital thermometer died during mash. Backup thermometer was broken. Third thermometer broke during use. Mash temps (stepped) were definitely off. Keggle had damaged/leaky nipple that had to be replaced with a poly nipple resulting in unknown and screwy mash times. Sparge water calculations were somehow off resulting in need for longer boil. Managed to come in about a quarter gallon shy of my target and (likely due to volume difference) slightly higher than target gravity.

Pitched Nottingham yeast at 72F using the carboy "fermometer" as a temp guide. 12 hours later it was at 75F, ambient temp was in low 60's. At 20 hours came home to find it at 78F and ambient temps in mid 60's. In morning ambient temp was mid 50's but fermometer was at 81F. I moved the carboy into a cold water bath and covered with moist towels. 8 hours later it was down to 71F where it has stayed for the last three days.

So the question is, when I get to bottling what temperature should I use to calculate pitching rate?

Normally I've used the fermentation temp (which has always been +/-2 F before this screwy session) and had mixed results. Currently have an over-carbed IPA and an under-carbed Kolsch in bottles. Kolsch was racked to secondary and cold crashed for 14 days at 38-40F. This thread helped a bit, but I'm generally confused for a brew that was all over the place in primary fermentation.

Thanks!

Always use the highest temperature that was reached after active fermentation stopped.

Thanks JuanMoore - The premise is that at the highest temperature the greatest amount of CO2 will have escaped from the wort and then later from the carboy as it (presumably) cooled? Still find it a bit confusing with the different calculators that specify fermentation temperature, current (bottling time) temperature, and the warmest temperature. I'm noticing that the kolsch referenced above tastes a bit sweet so I might try gently agitating and rewarming the bottles to see if it will fully carb.