Don't think it should end this way
1. Sara isn't free. She's on the run and they are too since they obviously didn't go separate ways. Being on the run is a terrible way to live and you'll be caught eventually. You can never talk to people or stay in the same place. It doesn't matter where you hide.
2. Who's to say Michael can't still be alive because of some miracle, we've seen them cheat death how many times. Getting to where this could go in a second...
3. How could the company be finished just because some old guy got thrown in prison?
My idea is that someone from the company has been sent into the prison to capture Michael, knowing they were escaping. Maybe they killed the officers chasing after him or maybe.. they were the officers. When they find Michael half dead they take him into care and with their advanced medical care they can help him stay alive - but at the same time brain wash him to be apart of the company. (Not hard to believe as this is what they did to others.) Someone tips off Burrows and you can see how it would continue from here.
I know they won't continue the show but it would be nice to discuss how it could continue