Let's look at the proposed British terms of August 1814:
"Within a week, Lord Castlereagh sent precise instructions which confirmed the worst fears of the Americans. The Indian boundary line was to follow the line of the Treaty of Greenville and beyond it neither nation was to acquire land. The United States was asked, in short, to set apart for the Indians in perpetuity an area which comprised the present States of Michigan, Wisconsin, and Illinois, four-fifths of Indiana, and a third of Ohio. But, remonstrated Gallatin, this area included States and Territories settled by more than a hundred thousand American citizens. What was to be done with them? 'They must look after themselves,' was the blunt answer.
"In comparison with this astounding proposal, Lord Castlereagh's further suggestion of a 'rectification' of the frontier by the cession of Fort Niagara and Sackett's Harbor and by the exclusion of the Americans from the Lakes, seemed of little importance. The purpose of His Majesty's Government, the commissioners hastened to add, was not aggrandizement but the protection of the North American provinces. In view of the avowed aim of the United States to conquer Canada, the control of the Lakes must rest with Great Britain. Indeed, taking the weakness of Canada into account, His Majesty's Government might have reasonably demanded the cession of the lands adjacent to the Lakes; and should these moderate terms not be accepted, His Majesty's Government would feel itself at liberty to enlarge its demands, if the war continued to favor British arms. The American commissioners asked if these proposals relating to the control of the Lakes were also a sine qua non. 'We have given you one sine qua non already,' was the reply, 'and we should suppose one sine qua non at a time was enough.'"
http://books.google.com/books?id=lFClPeG-IowC&pg=PT212
See
http://avalon.law.yale.edu/18th_century/greenvil.asp for the text of the Treaty of Greenville and
http://score.rims.k12.ca.us/score_lessons/treaty_greenville/media/treatygreenvillemap.gif for a map of the Greenville line.
To insist on this 1795 line in 1814 seems amazingly unrealistic in retrospect, but remember that in 1814 "Britain and Indians still held Michilimackinac, Prarie du Chien on the upper Mississippi, and most of Michigan and Wisconsin. With Wellington's veterans preparing to embark from French ports and the United States on the verge of bankruptcy, fighting its most unpopular war, Britain and the Indians became optimistic about making territorial adjustments." J. Leitch Wright, Jr., *Britain and the American Frontier 1783-1815* (Athens: University of Georgia Press 1975), p. 167.