This short trip worked out perfectly, a few random thoughts for others who might be thinking about a GAP trip:

• Real (tm) cyclists have done the entire GAP in 1  day. On the other end of the spectrum, splitting the 150 miles into a leisurely 5 or even 6 day trip is common. For my purposes, a 2 day trip was about right but I think a 3 day (Pittsburgh to Connellsville to Rockwood to Cumberland for example) is really good mix of decent daily mileage and time to do more than just ride.
• Covid has hit the small trail towns pretty hard, with many businesses closed or ending their seasons after Labor Day vs. staying open through leaf peepage season. West Newton, Connellsville and Meyersdale are pretty reliable still - if you are planning food stops at the other small towns, check in advance.
• In 150 miles, there was maybe a total of 1/4 mile of bad surface, even on the Maryland segment. I've done GAP rides in the past on 32mm tires and it was marginal - with all the resurfacing and maintenance in recent years, definitely could have gone with those tires this time.
• The Great Allegheny Trail Conservancy has a very useful web site here.  The interactive map is usually the most up to date and they have a trail alerts section that is usually pretty current, too. The listings for lodging and food are not necessarily complete or up to date - better to look at Tripadvisor or Google for lodging/food planning.
• The first few miles out of Pittsburgh, and the route through McKeesport are pretty confusing - though maybe less so if you are going East to West.  Usually pretty easy to guess the right way to go in both cases and there are some YouTube videos that you can watch about getting in/out of Pittsburgh on the GAP.
• Even though warming has meant the first freeze is much later than the historical average, many of the rest stops still shut down their outdoor water fountains in mid-September. In most of them, you can still fill up inside the visitors center in the restroom.
• I mentioned I don't really like to stop, but I do stop every time at the Meyersdale Visitors Center - don't miss that.
• Amtrak is a great bargain but a lot of the online information about bringing bikes on board is confusing and out of date. The easiest way to get the straight skinny is to call Amtrak, wait on hold and talk to one of the real live human ticket agents.
• The bike packing setup works for me but would have made it hard to even add one more souvenir T shirt and still have enough room to carry a rain jacket.
• The Great Allegheny Passage group on Facebook is a great way to stay current on GAP and C&O Canal Towpath conditions.