For some while I've been playing with a multisite network on a local setup using MAMP. Now I'm having doubts about whether it's best to continue building the website entirely in the local environment and later migrating to the server, or to set up a dev environment on the server. Problem is, the build is to replace an existing website, which needs to stay up till the replacement launches. Either way, I'll need to test the WordPress multisite on the remote server. Please can anyone advise me what is the best way to proceed? Should I use one of my domain names and set up a separate webhosting account for development? If this were going to be a simple WordPress blog, I'd use the existing website's account and simply install WordPress into a subfolder and later migrate. But this is a multisite installation, and I want to install using subfolders rather than subdomains.
And when it comes time to launch the new website, will it be as simple as pointing the existing website's DNS to the new website, or will I need to do an extensive search and replace for all urls?