ESB did not upgrade to 100A fuse

As others have said if you time things right and have at least one load sensing charger you should be ok.

Dishwashers & washing machines mostly draw high power for first 10 minutes of operation do slightly stagger their start time. The charger for each car will take 7kW as long as lots of other things are not on. It will slow charging if lots of things on at same time, but after 10 minutes then dishwasher water will be hot, the washing machine water will be hot and there will be excess power.

If your commute is say 110km a day you need around 20kWh if energy into the car or 3 full hours charging at top rate. If your commute is less than this 2 hours a night may be ok, but it may take multiple nights at cheapest rates to fully fill back up the car.

Beware clothes dryers are high consumption most of the time but if using it nightly you should get a low power heat pump model. Ideally set limits way beyond the main fire limits, for most average houses you want a 50amp max continuous draw, and ensure you have lots of smoke alarms if running everything at night. I have 9 radio interlinked battery & heat detectors to wake everyone up if something starts to smoke in the middle of the night. I have already had the "professionally" installed EV charger isolator melt inside as presumably the screws were not tightened correctly.

When I contacted ESBN they said in most cases there is no cost to change from 8 to 12kVA.