re: What would you do with your winning lottery ticket while getting your affairs in order?

It’s a bearer instrument so you sign the ticket immediately then you get a lawyer.

Not Jim Bobs law firm down the street or the divorce attorney your cousin used, you contact a real deal law firm like Latham, Skadden, Kirkland, or Cravath and explain the situation and ask to speak to head of their trust practice.

Then go from there.