Yes you need to change your Tyre immediately, even if you are not travelling to north
I thought you are travelling with a child, so that's why I said no problem. with four persons it could be an issue never went there with four person so can't say much.
you can do following check weather it will be an issue or not,
Measure the height of your car from ground just ahead of rear tyre, with four persons and two persons if difference is not much then i think it will be good to go, preferably those persons who are going with you.