Large OpenWorld Creation

Hello,
I am working on a project but i am thinking a LARGE openworld map something like 120km2.

Several questions i have here

  1. can UE handle a map that large? if so what is the best settings to handle that size?
  2. I will not be releasing the full map at once , I would like to work on the project section by section but release a smaller playable area for testing while the other areas are being built. How do I achieve that?
  3. I would like to use a map vector image i have created in illustrator, anyone know best way to use that image? or have tutorial links?

Thank you for all the help