My wife did LeJog a few years ago. For training try and ride for several days in a row, doesn’t have to be hard riding, a few hours at endurance pace will be enough. Just riding at weekends means you only get used to riding for two days in a row.
Eighty miles isn’t that far if you break it down - breakfast, ride a couple of hours, café stop, ride a couple of hours, lunch, ride a couple of hours, café stop, ride to evening stop.
My wife followed the CTC route which does two longish days then a short day which is a reasonable way to do it.