How to deal with the COVID-19 outbreak while organizing a conference?
Regarding remote conferences, these have been successful. Often the motivating factor has been mitigating climate impact. For example, Yale Climate Connections wrote an article giving advice for running virtual conferences. Author Sara Peach presents three kinds of virtual conferencing, all of which have been done successfully: 


remote presentations in a traditional conference format. If people choose to not travel, they can still remote in or follow the session on social media. (Example: AGU)
hub-based conference, where people gather in regional clusters. Each hub has some of its own content but are able to watch each other's presentations. (Example: International Conference on Music Perception and Cognition)
an entirely remote conference, where people record and upload videos of presentations and conferencegoers have weeks to ask questions and interact. (Example: A Nearly Carbon-Neutral Conference Model)


I'll add that an entirely virtual synchronous conference has also been done successfully. One example is NACADA, the Global Community for Academic Advising, which ran a 24-hour live-streaming virtual conference. 

The mixed-conference or hub models may or may not be feasible, since they would still involve people gathering in some models, and you aren't sure yet whether that will be feasible on any scale. Also, developing regional hubs would take time you don't have.  Thus, if you decide to go entirely virtual, a synchronous-with-live-streaming conference and a asynchronous recorded approach have been done, and the resources linked should provide a way to start researching or planning that model. I also advise contacting your own IT department about the possibility.