It is entirely possible. I know a woman who lives in the same city as me, who developed SFN after a gastro virus. However, I think her onset was a little closer to her virus. Her symptom picture is very significant so she ended up in pretty rough shape.

Also, she had about 4 months of intense progression of symptoms, then it tapered off. So I guess she falls under the camp of having a sensory variant of GBS.