Web Hosting Packages / Capacites for high volume traffic



I am looking for additional information about the 3 hosting packages that DH offers, and their respective capacities for high volume of website traffic. I am currently using the Shared Package.

There is a strong likelihood that my website will experience a sharp spike in traffic in the coming months, when a current client/project goes public.

I would like to know what steps I can take to preclude my site from crashing, and whether upgrading to the VPS or Dedicated plan is advised. All three plans are stated to have Unlimited TB Traffic, however I’m not clear on if that means a server cant be overloaded.

Thank you.