Given the data and research that goes into these sorts of high dollar races, I suspect it wouldn't be very interesting. It would be a relatively simple calculation (that I cannot do and do not know all the variables for) to determine when the benefits of batteries clearly outweigh the benefits of combustion engines with quick and simple refuels. These teams know exactly how many laps they need to complete and the speed they need to do it in order to be competitive. They track the fuel and refuels and other pit stops very closely, so as soon as they can see they would benefit from batteries I'd expect almost the entire fleet to switch over. There will be almost no overlap between electric and combustion cars in races.

The only benefit combustion engines have is the current faster refuel and run time. Everything else about electric motors is far superior to combustion. If and when F1 can hot-swap battery packs efficiently, combustion engines will be dead in that sport.