Did a similar top down shot of two characters in bed recently with an F65. We used a Dana Dolly with 6' speedrail and combo stands on either side of the bed. We tied off the camera and stands with sash cord and counter weighted the camera with a sandbag and a cardellini off the back of the camera platform. That was a 75 degree tilt down, not 90. Having a ultra wide lens helps, since you don't have to go up as high. I used a 12mm Ultra Prime in this case, but I've also done it with a Tokina 11-16, works great.
For something more secure with a heavy camera, you should use a 90 degree tilt plate and attach an Arri dovetail or quick release plate system directly to the tilt plate itself. You lose a bit of quick adjustability but it is definitely safer. I've gone up almost to top floor on high rollers with an Alexa that way, it works. Here's what the tilt plate looks like:
With a Scarlet, it's light enough when fully stripped it down that you can use two baby pins to mount it to gobo heads. Just run a cable for AC power and a BNC for picture. If you have a Redmote or extra long EVF cable for the Touch screen so that you can control the camera from the ground, even better. Put a 3/8-16 pin in the base and another 3/8-16 of 1/4-20 in the cheese plate on top or on the handle. You need at least two mounting points for stability and safely. Just remember that the safety of cast and crew is always your #1 priority.