I finished up the game tonight. I won’t get into the details but here is a picture of the action at the end of turn 7 and then at the end of the game.
On turn 9, I made a mistake allowing Red to advance another infantry toward the enemy. This, by rule, is not allowed once your exhaustion point is reached. the game should have ended with a marginal victory for Blue as they did hold 1 crossing.
Artillery was key. Blue got a phase every turn where they got to fire and inflict casualties on the enemy without reply. On two of the turns, both guns missed but otherwise, they scored at least one hit on each of the other 8 turns.
Based on this scenario, I’d say 10 turns for One Hour Wargames game length is about right.