If dad passes away before we can get DPOA in place, what do I do?

Yes, I don't see the need of a DPOA if Dad is dying. If its to make decisions for him because he can't, too late for a DPOA. He has to be able to assign someone. Like said, DPOA is voided upon death. At that point the Executor of the Will takes over. If no Will, then someone needs to go to Probate to be assigned Administrator of the estate. Doing everything an Executor would do but...the State determines who inherits.

The PoA authority (if one is given) ends the moment your Dad passes. If you are concerned about a Last Will, in order for a will to be valid, the person creating and signing must have "testamentary capacity," which means he or she must understand the implications of what is being signed. Whether or not it needs to be witnessed and notarized may depend on the laws of his home state.

If Dad is not completely with it and competent it is too late for any kind of POA. A POA is conferred by someone who is competent. A Lawyer will come to the bedside. Call Lawyer and ask if they will do this. What do you want this DPOA for? Health Care or financial???? If you fear Dad will pass before this can be done, and there is no will done, then the relatives can go to the court and ask that the most competent be installed as administrator of the estate. Then that person will be made "executor" and the estate is sold, gathered, and divided among the wife, siblings according to the laws of the state. Call an attorney, Elder Care or Trust and Estate on Monday. IF Dad is competent.
If this is a hospital setting the Social Worker on call on Monday may be able to get you emergency guardianship in moments with a call to a judge. Depends on your state. Contact Social Worker first thing in a.m.

Explain to the attorney the urgency of the situation, and ask for an expedited visit.  He/she can meet with your father, have the documents prepared and return in a day or two for execution.    Some attorneys will bring witnesses and a notary from their office, so you might ask about that.