The first solution that comes to my mind is to put your 17 year old in charge unless you have doubts about their ability to manage it properly. Perhaps provide a reward of some sort if it's handled well. Provide a few emergency phone numbers, especially nearby neighbors. I feel like a 17 year old should be able to handle this.
Another solution might be to find a "sitter" -- perhaps a referral from friends or your church -- a grandmotherly type or a college student? LOL...an Eagle Scout with a list of references as long as your arm?
A list of pros and cons helps me to make tough decisions.