As I understand, as stated in the Model Y Owner's manual, the Navigation System partially bases the estimated consumption on the vehicle's driving history. I.e. if you consistently drive 70 MPH but then change your driving style and drive 80 MPH the system does not recalculate consumption based on the new higher driving speed. In this use case A Better Route Planner would enable you to enter your average and maximum driving speed for a planned trip. ABRP might determine that one or more additional charging stops will be required.
Another strategy is to add 10% to 15% additional battery charge before starting a trip leg to bump up whatever arrival state of charge the Tesla Navigation system estimates while knowing that due to faster driving speed the actual arrival state of charge will be lower, close to the original arrival state of charge estimated. I encountered this recently while using a Supercharger on a trip. The Tesla charging system displayed a message that my Model Y had enough charge to reach my destination (but with only ~10% arrival state of charge). I was not comfortable with this arrival state of charge. I ignored this message and continued to charge and add an additional 10% while Supercharging.
Yep, I've been doing that. It would say the car is good to go with 20% SOC at next stop. I let it to another 10%. But then I would arrive with 20% SOC instead of 30%. Too bad Tesla does not allow us to adjust the projected speed like in ABRP.