The fact your even asking this shows something is up when comparing the AWD and P cars.
There isn't a single combustion car I can think of where a car that can pull away so easily on a 0-60 run gets pegged so badly by time you get to 60mph+.
Going from a 100bhp to 200bhp car gets you quicker 0-60 times, up to 300bhp and the difference is how quickly 80-100mph arrives, 400bhp and your playing with the big boys at three digit acceleration figures which is where you really need BHP to show a difference and pull away.
A car like the P Model 3 *should* be walking away from the AWD version at 60mph given the massive 0-60 difference, almost regardless of SOC. The fact it cannot tells you Tesla is fiddling with power figures some where, either the AWD is been limited or the P is.
For UK public roads usage I would say 300bhp is more than enough, anything more than that and your chance of lossing your licence/causing a horrific crash is pretty high.
Its not uncommon for people to do 50mph on the Mways - like a Leaf driver, you can easily end up with a closing speed of 70mph+ if your in a car with 400bhp with AWD and not even realise, add in a bit of standing water and slight curve and you have a recipe for disaster.
But forget road safety for a second, I don't even dare our 75D X at full throttle on the Mways for more than 10 seconds for the sake of my license, unmarked police cars, fixed cameras, speed camera vans, even some do gooder with a dash cam can get you in trouble far too easily.