What if the Cuban Missile Crisis had escalated to a Declaration of War by the USA against the Soviet Union?

In October 1962 the USA became aware that the Soviets had installed SAM sites and ballistic missiles in Cuba. On 27 October a U-2 reconnaissance plane was shot down by a Soviet missile crew. As a direct result of this action, US military forces made the decision to retaliate within 24 hrs of the shoot-down. However, president Kennedy stayed his hand and the negotiations continued. What if the negotiations had failed, the US declared war and then proceeded to a full-scale invasion of Cuba?