[Membership 2 Pro] Changing site URL from icpic.org to members.icpic.org, need help managing PayPa

icpic.org has a few hundred recurring memberships; a new development contributor wants to split off the membership-dependent content of the site. So the WordPress / Mem2Pro portion of the site will now change from icpic.org to members.icpic.org.

The challenge is that PayPal still has the plain icpic.org IPN destination URL, for all those 100s of recurring subscriptions, and my previous experience with PayPal is that there is NO way to change that association.

Is there any chance the plugin itself handles such changes of address ... in other words that the plugin (re)sets the IPN destination automagically each time an existing subscription renews? I'm not wildly hopeful in this regard, as I think from my read of the PayPal recurrence API documentation, that each renewal originates at PayPal's servers, not the site server (and so the old/wrong URL is baked in before any modification can be introduced at the target site), but it can't hurt to ask.

If not, is there any other way of handling old-URL IPN renewal requests so that they continue to function under the new, divided DNS scheme? To clarify ... browser requests for icpic.org will route to a NEW server (a non-WordPress build, where perhaps I could set up a redirect order in .htaccess to reroute traffic from PayPal IPN IP ranges to members.icpic.org).

Thanks for your timely assistance, :Benjamin