Bottom line: Summer tires do not function well below 50F, period. Has nothing to do with whether you have snow or not. Of course, winter tires have an added benefit in that they will aid in traction in snow and ice.
The advice given in this thread are not opinions, they're based on fact. Nobody here wants to read a post where a forum member wrecks their car because they don't heed good advice.
In the end, it's your car...do what you want. But you better hope you don't hit someone because you lack proper tires on your car...you will pay dearly for that. That is all.