You should be fine if it was properly winterized last year. Like jkust said, the engine block should always be drained first. I always pump antifreeze through engine block, because you can always have a little water stuck in the block or exhaust, and it doesn't take much water to freeze, expand, and damage something. If you don't drain the block first, you will mix anti-freeze with the water in the engine and either take twice as much to get it through the system or be left with some water in the block. The good news is since it already sat all winter, if it didn't crack your block, I would guess it was done right! To answer your question directly, if done right last year, and you never started it or touched the motor, you should be fine to let it sit another winter. Maybe add some additional fuel treatment though.