Heretic of The Seventh Circle
Empire - remnants - First Order was not overnightFrom the other canon there's no empire. In this they say episode 1 there's no empire only warlords.
Empires already surrendered after Jakku, the First Order seeds are already out in the unknown regions.
In the new canon they haven't been very clear on the leftover imperials that didn't go join the 1st order.