Hi Eric,
Plattsburg is definitely on my War of 1812 gaming to do list. However, based on the OOB of the contenders it may be a challenge to avoid a British blow out of the American defenders. As an aside my historical view is that Prevost threw away a certain victory and ultimately paid the price for his lack of vigour.
If one is going to conduct the naval element one could roll the dice (or multiples) to decide with varying degrees of victory or loss. Alternatively, a proper naval game such as the gun boat rules from "Captitan" could be played out to decide the naval portion of the engagement. How any remaining serviceable ships would affect the course of the land battle would have to worked out. My instinct is that it would have little effect in the short term.
Even if you ignored the naval battle (except for the gunboats on both sides, contending ships of both sides had battered themselves to wrecks, so they were not going to have much immediate effect on the land battle) you still have the problem of an overwhelming and mostly battle hardened British/Canadian forces of 10,000 versus approximately 3,000 not so experienced regulars and perhaps 3000 inexperienced militia.
My solution must unfortunately necessitate a 'what if' scenario. The what if refers to Major General Izard's army of just under 5,000 regular troops of all arms. The what if is that Izard, in certain knowledge that Prevost was moving a large army to attack Plattsburg (which is true) takes the imitative by ignoring Armstrong's order to move his army to Sackett's harbor and returns to Plattsburg (or never leaves).
To war-game this one could dice throw both the time of the arrival and where. The where could be from along the Saranac River or from Champlain and Chazy, the latter would interfere with British lines of communication. However the latter could bring in British and Canadian forces that were stationed along the route.
Those are my brief thoughts on a possible Plattsburg war-game. I too would appreciate other ideas.
P.S. We still need a War of 1812 Board.