The population of Lubbock, TX on the sign reads WAS 229,573. This places the year of the sign circa 2009-2010, as the 2009 population was 225,859 and the 2010 population was 230,710. Since these signs are usually not changed annually, this would place the blackout around the same year the series began in 2012. Adding known information, this would make the year depicted circa 2028.
To get a perspective of the travel time involved, walking from Hollis, one of the closest towns in Oklahoma, to Lubbock Texas would take around 55 hours. Walking from Peoria, one of the furthest away, would take 184 hours. Presuming Aaron and Priscilla walked at 2 MPH for 12 hours per day, they would cover 24 miles per day. The shorter trip would take a little over 2 days while the longer one would take a little over a week.
The Aumont shown in season 2 Episodes 13-15 is a historic building in Seguin, Texas. Originally a hotel, it now houses a pub and ballroom (where the congregation met on the show) on the first floor with offices and apartments on the upper floors. The locals claim that the building haunted.