I am in poor health and can't get life insurance. Am considering getting married and wonder if there is any way to protect my wife should I accumulate catastropic medical bills. Would prenups have any ability?

This will depend on your nation you live in.

Some couples I marry, prefer a non traditional wedding, we give them a church wedding, but not a state wedding, to the state they are not legally married, if the lady wants to change her last name, we have them do a state name change for about 250 dollars.

Each couple writes a will, a power of attorney and a living will. This gives each other as close to the rights of being married as you can get.
After the death of one part, the other will have to pay any money the other party has for any debts, but will not lose their own property or money.
Joint accounts in both names may still be taken.

Many older couples do this, since at one time and I believe still, they will lose some social security benefit being married over single, they don't want to live together in "sin" but can't afford the lost of money or the liablity of debt.