Networking with cells

What we want / have

-We want to create a game which has a large world (27x27km or larger).
-This game is an online game, therefore, our solution must work with other clients as well.

To maintain precision, the game world will be split into 3x3 cells. The surrounding cells will also be loaded (total of 9 cells).
-As a user moves out of one cell and into another, the 'surrounding' cells will be 'updated' (old ones unloaded, new ones loaded). We want this to happen seamlessly.

This works fine for single player, but when we are doing multilayer this causes an issue.

We have had two approaches to the networking, and they are as follows:

Solution 1 The client connects to a 'shadow world'. The shadow world is comprised of 'cells'.
Solution 2 > The client connects directly to multiple cells. As the client moves around in the game world, it disconnects and reconnects to different cells. - I can't think of a way to do this. >
Shadow World. > > The shadow world is comprised of the main cell (cell that the client exists in), and the surrounding cells. The shadow world speaks directly with the client, and poses as a 'gateway' between the client and the cells by organizing the information. > Cells > > The cell is an individual 'unity instance'. In a normal unity networked game (cells are not an issue), this would be the 'server'.

Anyway, I am totally stuck at this point, I'm not quite sure how to make it work. I'd like to use the built in unity networking. Are there any examples or working projects that use 'cells' so-to-speak?