The data will carry over from update to update without you having to do anything. Renpy reads from a specific folder located in the APPDATA folder. As long as that data is altered, it'll carry over. You can also back up your data from there.
I was actually wondering about this, it's been updated since I last played and I haven't bothered to re-download.But since there's going to be another update pretty soon I'll probably wait until then anyway.
