Measured on the iOS 27.1 simulator. Drawn to scale.
Status bar, top 82 pt (time, battery, signal, top right corner). Can hide: yes. MiniMac already hides it on the stream screen in this pose, so the Mac screen gets the full top half.
Fold, 40 pt band across the middle (y 455 to 495). Can hide: no. It is the hinge. Nothing tappable goes there; we can paint the MacBook hinge or a bezel into it.
Home indicator, bottom 34 pt. Can hide: partly. The bar can fade out after a few seconds and we can make the first swipe up not go home. But a swipe up from the bottom edge always goes home in the end, so no keys or trackpad edge down there. The palm rest under the trackpad fills it, like a real MacBook.
Under-display camera, left edge of the top half. Takes no space: iOS only reserves it while the camera is on. A few Mac pixels sit over it.
Yours: top half 669 × 455 for the Mac screen, bottom half 669 × 421 for the keyboard and trackpad.
Fit: 669 pt wide gives MacBook keys about 44 pt wide. A short function row plus 5 full rows is about 255 pt tall, which leaves about 160 pt for the trackpad. Tighter than the first estimate, but it fits.