Look into photorespiration and it might change your mind on running high temperatures, especially in flower...
A lot of that high temp talk started when LEDs became really mainstream and companies like blackdogled recommended 86 °F temps in flower for less HVAC (Air Conditioning). It's a sales pitch I doubt it's in your plants best interest.
Big buds are going to happen with the right genetics even if your room is cold. Lighting, Environment (temp, humidity, airflow, co2 etc) and proper rootzone pH & Nutrition is going to play a huge role. If you want to sift through the bro-science look into c3 plants mode of action, it will explain that the enzymatic processes and photosynthesis occurs best within the range of 68-75 °F or something like that.