Cut and stack the trees. Now you have bunkers, cover to bunkers and opened up firing lines. Some by the house and you've hardened your walls.
All that snow is free water. Although with a bobcat I'd might make a pond.
I'd have my people practice shooting where their bunkers are and markers to adjust sights.
That slight hill in the background has the high ground. Others would have a better idea how to counter or utilize it.