Yes, create the ESP32_FTPClient object dynamically in setup().
ESP32_FTPClient * ftp;
...
void setup() {
...
ftp = new ESP32_FTPClient(ftp_server, ftp_user, ftp_pass, 5000, 0);
Note: ftp
is now not the object itself but a pointer/reference to it, so you will need to de-reference the pointer when you use it in your other code:
ftp.doXYZ();
becomes
ftp->doXYZ();