I know that this is probably the most common subject to talk about pre 1900 alt history apart from the byzantine empire surviving, but I want to know what could happen if Napoleon allows russia to break from the continental blockade and keeps his defensive posture in Europe, maybe using Le Grande Arme to fight in Iberia against the british and Portugal. Could he stall the war for enought time for a definitive peace treaty be signed? And what would happen to the continental bloc eventually?