I found that Prof Ken Sikaris is a good explainer of this dilemma.
Cholesterol is only the transport system for fat energy, i.e. the tankers and delivery trucks taking fat to and from the liver. The process of getting fat from your meal and into the liver is separate from this and is not measured in the TC that the GP is looking at. The two processes are unconnected.
TC is describing the Local deliveries from the liver stores out to the local filling stations in the body ( i.e. body cells) for immediate use. Normally the body only manufactures the amount of LDL we actually need to meet our needs at the time and manufactures HDL to act as the recycling trucks to match. This is not really dependent on how much fat we have just eaten, although the liver will use the digestion time to top up the essential stores in the adipose tissues so we protect our vitals, and this is why the lipid panels should be Fasting Blood Tests.
TC will be higher on cold days because the liver will be working hard to top up the brown fat cells that keep us warm in winter for example. TC will be higher while you are losing weight by fat burning But the ratio should remain similar all the way though. TC will be lower if you are burning energy from carbs or have a high blood sugar level I think, but could be wrong, that TC also goes up during endurance exercise since our bodies switch to burn more fat ( second wind)