How big of an area should I shovel out for my girl?

First, my girl is a 5 year old Golden Retriever. We got 16” of snow on top of the 8” we had last week. I shoveled out a 20’x15’ area in the yard for her to go do her business. The snow was covered in heavy thick ice, which made shoveling difficult. I made her a nice little path to her spot. She’s fine using it to pee, but she’s not liking it for number 2s. Is the spot big enough for her or should I try to expand the spot? She keeps circling the perimeter, like she has to go and tries to tamp down the edges by circling. She’s not able to go in the deeper snow because she sinks and will not go potty because of that. I was just curious how big an area she should have. What do you do for your dogs when you get a deep snow? Thanks in advance!