@REI-JohnJ pointed me towards your post. Happy to provide a few thoughts. As he mentioned, I did a number of mid winter sled hauling trips in the Alaskan arctic.
I didn't ever measure my calorific consumption while training for the trips but like you, I hauled sleds on hilly bitumen roads for several hours a day in the months leading up to the trip. In addition to developing stamina, I was trying very hard to strengthen the ligaments in and around my knees as i felt that they were my weakest point after many years of heavy load carrying in the Himalaya. I started out with a 4 wheel drive tyre on dirt tracks but quickly changed to bitumen to get the necessary resistance. I then moved up to a truck tyre to get sufficient weight.
Our food consumption was designed to fuel us for both the cold and energy expenditure. Calculations were based on data provided by Antarctic adventurers and some military research. It's worth noting several key points. Firstly, we were pulling heavier sleds than you are likely to have, given that we were out for several months. We were being resupplied every few weeks but the amount of fuel and the weight of sleeping equipment necessary for constant -40C and frequently colder temps, was extraordinary. About twice what I'd normally use on a Himalayan mountaineering expedition. Secondly, it takes several weeks for one's metabolism to kick into gear to enable you to consume the calories that you actually need. So calculations for long expeditions like ours worked on what we could ingest for the first couple of weeks, then increased about 10% for next two weeks, then increased another 10% and so on, until it was about 130% of the original allowance. We had to do it that way because at the start we simply couldn't consume the amount of calories that our bodies would demand when our metabolism caught up. On a short trip like yours, you'll be able to stay on the same lighter calorie intake for the duration of the two weeks. Indeed you could probably go quite light on the food and just lose weight.
We calculated a need for 6000 calories per person per day (yes calories not kilojules) at the start. That eventually built up to 7500 calories per person per day. As yours is only a 2 week trip in what i assume will be warmer conditions than the arctic winter we had, your demands should be less. Our food consisted of high energy, high fat, high protein items and we allowed 1kg of food per person per day. Brekky - oats, butter (or olive oil), milk powder. Snacks through the day - nuts, probar meals, chocolate, cheese, dried meat. Dinner - 2 to 3 serves of freeze dried. Most fats were consumed at night when best digested.
Hope that's helpful. Happy to provide more info if desired.