Use an orthographic camera tilted slightly left and slightly down.
Leave all your sprites on the x/y plane (z-normal plane)
Make the camera move along the x/y plane when the player nears one of the edges of its viewports. You can get the edges of an ortho camera’s viewports pretty easily just by adding a Z value to camera.transform.forward and offsetting it on the x axis for horizontal edges and the y for vertical edges. You could project that ray onto the gameplay x/y plane to get the exact points of the edges in the play area and calculate distance to the player each frame to check how close the player is to the edges.
Sorry this isn’t a guide, just a couple of high-level ideas No I don’t have code ready for any of this.