Due to the low population i would suggest one day a a week to be dedicated arena day for the server. When most people would know to come online to do some arenas like every friday or saturday 3pmish server time untill 8-9 so we wont be stack in dead ques for 1-2 hourse when maybe one or 2 teams would que.
Well, I guess that could work.
Outland is almost dead by now but on each tuesday before the flush it has still active arenas across all brackets.
If it works on TBC I guess that would also work on MoP to make at least the 2s bracket active on one specific day of the week.