Good point actually. Those who went to Colchester and got there early were treated to a live band playing outside and a section of the stadium which opened early so you could go to the toilet or go to the bar. This section had free access for all fans and was shut off from the rest of the stadium. Neat idea.
Think the Supporters Bar will be open early enough, whether or not you can get in is another matter though. Think they'll want everyone on the concourses as quick as possible though, rather than loitering outside