I can easily fit at 6'2" with my fiancé at 5'7" on the 2550 SX berth. You may want to look for a 265 SSI as a minimum comfortable cuddy size. The 215 SSI is tiny and the cabin isn't really usable.
You guys are brave winterizing that way 😁
I always drain and the back fill manually, making sure I fish the drains and see the AF come out before putting the drains back in. Takes longer, but is bulletproof.