Pro Sites: Switch to Stripe vs PayPal

Hi,
Currently running PayPal Pro and would like to switch over to Stripe and save $60 a month. The big question though is what happens to current recurring payments on Paypal? If they are on a quarterly plan, will their site die when I shut off PP Pro? I believe that PP Pro falls back to PP Express. Will they still be able to pay for the site via that? We can't have two payment gateways?
Thanks!