V.W.
You could at least ask your friends. You might be surprised by the response. They might feel quite honored to be asked to watch/keep your 2 year old on such a momentous occasion.
We had a friend keep our almost 3 yr old when his little sister was born. It was late at night, but they drove 40 minutes to meet us at the hospital and then took him home with them. Brought him up to the hospital the next morning to meet his sister. :)
You never know until you ask. And the important thing is that he is safe.
Congrats on your pending "addition". :))