Set up a configuration file for the server name. Modify each package to use the configuration file (yep, it's labor intensive for 100 packages). On the production server, put the configuration file in the path, and modify it for the proper server name. Then, just deploy your packages, and they will access the configuration file for the server name.

Oh - IMO, it would be best to load the server name into a variable, and use that variable as an expression in all of your connections.

What I do: I have a base SSIS package set up, that uses the configuration file, and has one standard connection. They are all set up to go - just add everything else you need to it.