There doesn't seem to be any way to adjust the build order if it extends past 5 items.

If I found a new city and immediately queue up new structures and a unit or two, it's impossible to drag a unit queued up near the end to the front of the list, because the tiny little build order in the bottom left of the screen only shows 5 items with arrows to change 'pages'.

If you go to the city details screen, you can see up to 9 items, but any past that and the arrows show up again, and its useless anyway because you cannot modify the build order from the details screen.

On top of all that, if you try to cancel an item on the second or later page, it immediately skips back to the first page - which means that cancelling more than one item at the end of the build queue is a royal pain in the butt.