How do I load the configuration from the production router to a backup router. The backup router is connected using only a console cable to a laptop. Since TFTP server uses IP and the ethernet port on the backup router is not connected, is my only resort to manually enter config line by line?
There are alternatives that are better than having to enter the config line by line. The easiest alternative is to log in to the primary router, do show running-config, use cut and paste to put the content of the config into a text file on the laptop, then log in to the backup, go into config mode, and paste the content of the config into the backup router, and then remember to do copy running-config startup-config to save the config on the backup.
That should work ok for you.