Make an ortho Camera covering the whole map + Render to texture?

As the title suggested:

How can i make an Orthographic Cmaera Component Cover the whole Map (in my scenario, a Paper2D Tilemap)?

I want to Have the whole map inside the Camera view AND render this to a 1:1 Texture + Save it as a PNG…
Like:
I´ve a 12892 Tiles Map - each Tile has a unit size of 4848 pixels. So the camera needs to cover a 61444416 units/pixel sized Map, and render to a 61444416 pixel texture, and save this Texture as PNG.

The idea behind is, to have the whole map as image, to create a Premade Lightmap in Photoshop with it.

Is this possible? If yes, how?