Here is one version of a “Canada” rule from the old Delta thread. Delta was a set of additional rules some people were trying to develop back before the final G1940.2 was finalized.
UK Europe government in exile.
The first time London is captured by an axis power, the capitol of UK Europe moves to Ottawa, Canada. The axis power that captures London seizes all IPCs currently held by UK Europe. The United States and Soviet union immediately join the Allies if they are not yet at war. Beginning at the Collect Income phase of its next turn, and as long as the UK government is in exile, it will collect income for all UK controlled territories on the Europe map. The government in exile may mobilize units only in Canadian industrial complexes.
Once per game, at the Collect Income phase of a turn when the UK government is in exile and London has been liberated, the Government in exile may return to London; or it may choose to remain in Canada. When it returns to London, the UK Europe government will continue to collect income for all UK controlled territories on the Europe map and on the following turn it may mobilize units in any UK controlled industrial complex on the Europe map.