We're about 30-40 odd years separated based on the ages listed.
We still do a fitted sheet, top sheet and a blanket, with a king size sleeping bag unzipped as a comforter on top, but we have an East-West style bed and are a good deal younger, so crawling in and working from the corners on the window side and backing out till we reach the step would likely be a bit more challenging for you guys.
Since the mattress sits in basically a bowl, the flat sheets and blanket easily tuck under the polyurethane foam mattress easily enough and stay put because they're being somewhat clamped in place by the snug fit of the mattress in the cabover.