That's where so many of our ptype forecast tools at the NWS offices fail. The one they are pushing everyone towards at the moment goes off max wet bulb temp. And +5C is enough to fully melt = lots of freezing rain. Not every model has the capability to provide probability of refreezing to sleet grids, which increase as your cold air magnitude gets larger.
Thickness grids attempt to get at it, but they are fixed and not ideal for all situations. Ideally we would have a functioning area above or below freezing tool to determine ptype. It's coming but it's there yet. And even then it would still miss low level snow generation, because it's looking from the top down.