Known overheat issues 4.7 RAM V8? EDIT FIXED
In my opinion 4.7 is a pretty sound little motor, 6 years and put 60,000 miles on it a total 111.000 the only problem I have ever had is a broken exhaust manifold bolt . But if it's overheat and then sub freezing weather something's going on. I would monitor coolant level as mentioned and be concerned.