Yes, the AI will still be seigeing you when you reload - it`s when you end turn that the trouble starts. Next turn they will walk away, like clockwork.

It isn`t even the seiges that affect you the player which are the real problem - it`s all the other AI seiges happening around the world. If you turn off FOW and look around the map in a game that`s a few years in, you`ll see the scale of the problem.