I don't see how having based aircaft would have anything to do with reliability issues. If the weather is below minima, it is below minima. EZY crews and jets are CAT3B capable. If the airport is not equipped then it does not matter who is flying it and where the plane is based, it is not landing, full stop.
It is pretty rare for EZY to chop a flight because they might not get in, more often then not they will give it a go. Compare that to BA who will can their entire domestic network at the first sign of trouble.