Is there any way to zoom a board in/out to see project status as a whole, at a glance?

Indeed - you can easily zoom in and out your Kanban board using the built-in zoom, available in Settings - Board Background.

Can I make my board larger?

Board Settings are only accessible to board owners and account admins/owners.

You can also use the build-in browser zoom.Just press the CTRL and + - keys (or CTRL and mouse scroll) to zoom in and out. To go back to the default view use: CTRL and 0.

Using the browser zoom will only rescale your own view of the board. Using the Kanban Tool built-in zoom will resize the board for all its users.

For more information, please read and article on making the Kanban board view larger.