I trained for a triathlon on keto (500m swim, 15 mile bike, 5k run) and as long as your pace yourself, youll be fine.
I always had a bottle of Ketoaid (recipe on this site) with MIO to add flavor! I think the main thing I notice on keto is that I cant go as hard as quickly; its more of a consistent energy that MAY require you to slow down but not stop. The cool feeling though is that even after working out for 2 hours, I didnt feel dead or tanked. I was tired and looking forward to relaxing and watching Netflix, but I didnt feel like I couldnt still go for a walk or have an enjoyable day due to lack of energy.
Electrolyte drink helped a lot and I even added a half scoop of MCT powder (lemon flavor) for an extra boost. My only warning when adding MCT powder is that it might give you slight diarrhea if youre not used to it.
But in general I would say dont shy away from a work out; go as regularly as you used to but dial it back if you must. Drink/eat your electrolyte supplements and just enjoy the exertion. 
PS. Once I was fat adapted, I actually did a practice run of the triathlon in a fasted state and I was able to complete it! It was much more tired afterwards than usual, but I had so much more energy during the main part of it if that makes any sense haha! I have since been trying more smaller workouts in a fasted state (usually fasting for 12-15 hours - just skipping breakfast) and I do feel like I have higher energy while fasted. Ive read articles that higher insulin levels correlate to lower energy expenditure since insulin is a storage molecule and often prevents nutrients from being burned for energy since its forcing them into storage.