I'm visiting Cape Cod in this June and need to get from Logan Airport (Boston) to Wellfleet (on the Outer Cape). I see there is a bus (the Plymouth & Brockton) but at the time I'd arrive in Logan, it would only get me to Hyannis (I'd arrive in Hyannis around 10 or 11pm). How likely is it that Uber or Lyft would have cars available at that time? (More generally, is there a way to find out this sort of thing short of requesting and cancelling a bunch of rides?) I know about the fare estimator for getting the estimated fare, but I'm worried about availablility.
At that time of night, and the distance, 35 miles, availability and 'book-ability' might be an issue, as @NateEldredge correctly points out. However, both services operate in the area and UpHail.com gives a fare range for Uber and Lyft of between $50-75 to go from Hyannis to Wellfleet.
As you may already be aware, taxis on the Cape can be very expensive but, if that is the only option at the time you arrive in Hyannis, Town Taxi is reputable, as is Cape Cab. There are many choices, but these are right in Hyannis, should you find yourself there with fewer options.
My choice for that route is the ferry, taking the first leg from the Logan Terminal B (stop 2/arrivals) by bus shuttle to the World Trade Center Pier for the Fast Ferry that goes Provincetown. The airport shuttle runs every 10 minutes. The latest departure is 6:30 pm.
Bay State Cruise Company runs the route three times a day, with the last departure at 5:30 pm; Boston Harbor Cruises runs twice a day, last departure at 6:30 pm. Both take about 1 hour 30 minutes to arrive in Provincetown.
From there, you're less than a 30-minute drive to Wellfleet. Both Lyft and Uber are more readily available in P'town, particularly in season, and would be about $25 for this ride, and a much more affordable taxi, should that be the only option by the time you arrive at the Ferry Terminal at MacMillan Pier. And Cape Cab has services from there to Wellfleet, as well.