I live in UK and winter season is wet to say the least - I just found a swimming pool in the back on my Cadillac in spare wheel compartment. It's not to close to the edge but not to far ether.
The way I see it my options are
Leave it. It might attract rust and overflow in to trunk where I sometimes keep my laptop and they don't go well with water. But if it does not in 2-3 months and weather becomes warmer and less rainy it might dry out by itself.
Take the tire out then get a cup and .... This will not solve underlying problem and might become a chore that I have to do from time to time. Still this is most straightforward solution with minimal possibility of doing more harm.
Drill a hole. This does sound like a permanent solution, but I am not sure what's 'under the ice', and what other bigger damage I could do. Other thing is - manufacturer could have done the holes and yet he didn't so there might be a reason for that.
What would be most appropriate situation?