AFAIK, the "power rationing" you refer to only applies to home charging points to electric vehicles - it does not apply to any other electrical equipment in a home
In fact the "rationing" is simply a random 10 minute timer that will prevent a surge on the electricity grid at 6pm - the time when most EV chargers switch on
All new home charging units now have to be "smart" so they can be controlled remotely to implement this random delay.
If you still feel the need to buy a generator, the buy an inverter generator.
They are more expensive than traditional generators but produce much "cleaner" power reducing the risk of damage to a lot of modern electronics
Also, when it comes to small generators "silent" and "diesel" are mutually exclusive terms

You might want to consider a duel fuel generator than can run on both petrol and propane
Cheers
Bruce