Monser - Put hot water into your blender whilst your coffee is being made. Then dump the hot water out of the blender just before you put the coffee/butter/mct in to blend. It'll keep the mixture hotter for longer, since you won't be blending hot coffee against the sides of a cold blender.
Preheat your thermos too. I think it's better to drink it warm or cold rather than ruin it in the microwave.
But what about my ratios of water to coffee? What do you guys do? I read on intro to BPC that you do you 2 TBSP per 6 ounces?? Seems very little water for the amount of coffee? DO you guys follow the instructions to the tee? Or have you guys found our own ratios that work for you?