Hmmmmmm. Looks like I was planning the trip about a week too soon. The shuttle buses don't start until 23 June. That was my backup plan in case we aren't up to the task. I think we can, but would like the option of putting the bikes on the bus if necessary.
Maybe we'll do the island line rail trail in Vermont instead and hit Acadia later in the summer. I checked and the ferry starts running Memorial day weekend. We wanted to do both trips this year anyway. And the Vermont one looks easier.