You can certainly wait till the 2nd since the cancellation charges will be same until then. As people seem to be suggesting it should confirm. However funnier things have happened and we have seen RAC1 not confirm. Can you live with that?
If you can afford it, I would suggest you keep it till the end. Its a really long journey and I would prefer to travel with full berth in SL than a half berth in 3A. Your preference might be different.