I carry enough battery for a day's ride, which is usually less than 80 miles. That way, I can charge overnight wherever I'm staying. B&B's along or near the trails I ride tend to book up well in advance. I have better luck booking hotels within a mile or so of the trail.
I don't have much info on the OTET yet but here's my take on the GAP Trail:
I've done the GAP 3 times, and do portions of it every year. It's by far the best ride east of the Mississippi.
I do the GAP in 3 days. When starting in Pittsburgh, I ride the 60 mile section to Connellsville and stay at the Comfort Inn, which is right on the trail at milepost 89.
https://www.choicehotels.com/pennsylvania/connellsville/comfort-inn-hotels/pa895
I ride 45 miles on day 2 from Connellsville to Rockwood, milepost 44, and usually stay at the Rockwood Trailhouse B&B.
https://www.rockwoodtrailhouse.com/ . As you noted, this one books up well in advance. Camping is also available in Rockwood at the Husky Haven Campground.
https://www.facebook.com/huskyhavencampground/ Take some time on this leg to explore the bridges & falls at Ohiopyle, and the bridges & tunnel at Pinkerton.
Day 3 is the 45 mile stretch from Rockwood to Cumberland, milepost 0. This section is the most scenic with the Salisbury viaduct, Keystone viaduct, and the Big Savage tunnel. If I'm planning to continue on to Washington DC on the C&O Canal towpath trail, I stay at the Hampton Inn in Cumberland, which is adjacent to the trail
https://www.guestreservations.com/h...q8iISsqf6ZJx3B5NixcagXDWQEBfc3cxoCSLYQAvD_BwE
The 150 mile C&O Canal Towpath Trail , which connects to the GAP, is another "must do ride" IMO.
A good link to conditions on the GAP:
https://gaptrail.org/?utm_source=Great+Allegheny+Passage+News+and+Alerts&utm_campaign=6d97b52c26-EMAIL_CAMPAIGN_2024_03_25_02_51&utm_medium=email&utm_term=0_-6d97b52c26-[LIST_EMAIL_ID]&mc_cid=6d97b52c26&mc_eid=f7355bc41a
I also recommend getting a copy of the GAP 2024 trail guide, which was just released:
https://gaptrail.org/before-you-go/trailguide/