A McLaren P1 replacement may eventually come in the form of a pure electric hypercar.
McLaren says it's still evaluating the possibility of an all-electric hypercar as a P1 PHEV replacement in 2023 or so.
McLaren P1 At Amelia
"McLaren is continuing to evaluate all-electric powertrains and their implementation in future models, because of their relative simplicity and lower centre of gravity than combustion engines."
"The Woking brand has long hinted that its P1 replacement, due in 2023, could swap petrol for electric power, and its involvement in Formula E – where it supplies the drivetrain tech – emphasises its expertise in the area."
In 2016, McLaren announced its Track 22 strategy. That strategy includes a switch over to at least hybrid power for half the vehicles in the McLaren lineup by 2022. The strategy preps the automaker for an all-electric future too.
Mark Vinnels, McLaren's executive director for program development, stated:
"...in engineering terms, electric cars are beautiful."
“Suppliers in the battery industry are working flat out to improve the energy density of their batteries, while what we want are batteries with better power density. One promotes range, the other performance, and the more power density you have, the bigger the issues with cooling the battery pack.”
"McLaren Applied Technologies is supplying Formula E with a new generation of battery that offers significantly more range, which will negate the need for a car change mid race and therefore offers about double the range."
This alone leads us to believe that, without a doubt, McLaren will have a road-going, all-electric car in the near future.
Also of note (video below): A track McLaren P1 GTR was modified by Lanzante (and made street legal), and recently bested the NIO EP9's Nurburgring time by a couple seconds - with a couples asterisks. The McLaren was not technically a production/from the factory car, and it also used a different start/finish line (20.8 km for the NIO vs 20.6 km for the McLaren). Nonetheless, they both are very fast, and they both plug-in. Enjoy the side-by-side video of both plug-in supercars doing their record laps.