Hello, my name is XXXXX XXXXX I will be helping you today.
Your going to be fine on the engine block as long as you pull the boat out of the water. Outboad engines are self draining. And as soon as you shut the engine off, all water simply drains out of the powerhead on its own. If the boat was in the water, and the lower unit still down, you can have some lakewater sitting there in the exhaust portion of the engine. So if it going to have a hard freeze, with the possibility of the lake freezing over, you would definitely want to pull it. But if it was just a light freeze I would not worry about it. Other than that, the engine block is self draining and does not retain water, so you have nothing to worry about there on the engine block itself.
However, you did say something about having it tilted up. If it is titled up, and it rains, then that water can accumulated in the exhaust cavity in the lower unit. It would be on the inside of the lower unit, right behind the propeller. And if that water freezes, it would crack the lower. If you can have somebody go over and trim it down so it's level, or even throw a trash bag over it the lower unit, that would be best.
Does that make sense? If it does then that should do it here, and just let me know if the ratings box gives you any problems or if you can not see it. If not, or if you just need more detail on something, by all means feel free to reply back before doing the ratings.
If I don't hear back fro you, Thanks in advance,