Holiday Dilemma

Being retired, kids still living at home, wife works part time and we have pets. I want to go to Australia and rent a car to live in for a few weeks while touring around.
It costs a chunk to get down there, and the car, but if I take the family it will cost 4 times more.. actually way more since they need to sleep in hotels or whatever, so probably 20X more.
Should I ditch them all and go by myself, or just never go.