You can fat load instead of carb load to meet energy needs. If you have been under 50 grams of carbs for a year, you are already keto adapted and you will be fine with adequate sodium and fat and protein. You can get plenty of carbs from vegetables, some nuts/seeds and their butters, greek yogurt, and low glycemic fruits. That is all you need. Take coconut milk with you and a no sugar added electrolyte drink to refuel.
If you do this you can avoid the 'bonk' because you will already be in fat burning mode. You will also not experienec the GI distress some athletes suffer with when they can't even keep water.
The body is equipped to use two sources of energy; carbohydrate and fat. When carbs are low the body will switch to fat burning.
Even though a ketogenic diet (Induction) involves consuming very little carbohydrate, the body still stores carbohydrate in the form of glycogen in muscles. On a ketogenic diet, muscle glycogen stores are about one half normal levels. The muscles will deplete muscle glycogen quicker on a ketogenic diet, but this will only become an issue if you are performing high repetition and high set workouts that tax your glycogen stores. Whether or not you should consume a little carbohydrate to enhance your workout in the form of berries, nuts, greek yogurt is unknown because this is highly individual. You must experiment in training. I would guess that it would help if a little more low glycemic carbs are consumed along with protein and this might help your performance. But the more carbs you consume, the more likely you will throw yourself out of fat burning.