Marriott sometimes moves you up to Gold or Plat if you are within a few nights, so you may have nothing to worry about. You can call and ask. About ten years ago I was about three or four nights away from renewing Plat. I called and was told they had already renewed me for the next year.
Some years there is an offer to buy back your status with points. Others may be able to give your more details on how many points and whether it's been offered the past couple years. I'm LTP, so I've stopped paying attention to or receiving those offers.
My first year as Plat I was a few nights short. My friend's parents were coming into town, so I met them at a Marriott, checked in with them and they paid me for the room. Of course, I didn't sleep in the room with them, but I did get the credit for the nights' points. We went out to dinner one night and I picked up the check to make up for them not getting the points.