Can the entrances be raised to avoid standing water or high snow?
No. The entrance locations are an integral part of the design to keep wind and water out of the 2nd floor “bedroom”. No shelter will be useful to cats if it’s surrounded by standing water, or buried under snow. To ensure the cats can use the shelter year round, place the shelter in an area that isn’t prone to flooding, and isn’t isolated by flood waters. Also, if you’re in an area with extreme snowfall, consider spending a few extra minutes shoveling, or even walking a path to the shelter to make sure the cats can get in and out, just like you can!