You need to resize it, but you can do that during the installation process (or let the installer decide). /Should/ be no problem. But, as always, when fiddling with partitions: make sure you have a backup, just in case.
If i would have a space for backup, i wouldn't resize, but just copy data there, delete & create & copy back ;) I never seen such an option in etch installer (maybe i missed it). AFAIR there was just an option to use largest continuous free space. Regards, Atis