John Fredrick Parker said:Maybe this will be easier to judge if we get more specific: my rough idea is for the Peace of Amiens to hold (though tentatively at times) for about six years, until hostilities are renewed about 1808. In OTL, this was when the Mutiny of Aranjuez led the Spanish monarchy to seek Napoleon's help, and for Nappy in turn to install his brother -- I'm thinking this happens TTL, and leads to war with Britain.
Six years, I believe, is enough time for the FE to reinforce troops in the WH, and build up something of a navy in the region -- at least big enough to give the RN headaches while the FIA (French Imperial Army) creates havoc on the continent.
How does this sound?
The peace of Amiens will be hard to held on for six years. It hardly held for three years before the Brits broke it up and Napoleon started his idea of invading Britain.
Besides, between 1801 and 1808, Napoleon had to face the third and fourth coalition in which he crushed Austria and Russia at Austerlitz (1805) and Prussia at Iena-Auersterd (1806). Both of those coalitions had the financial contribution of Britain.
Even if Amiens holds, I'm not sure it will butterfly away the opposition of Russia, Austria and Prussia. With this taken, the Brits will be very tempted to broke the peace and form those coalitions.