In my experience the wars can go a lot faster than before. You just need to focus on taking the forts, and with artillery now giving +1 per unit vs early forts, they can be taken quite quickly. Additionally, I declared war on a broken Hungary who couldn't afford the fort maintenance, so I just had to park a unit on each province. That was the fastest war I have ever done, they offered me their wargoal province after about 2 months.