OK, just so everyone understands, this is not a SQL problem. The .NET Framework has a special data type for SQL databases in System.Data.SqlTypes.SqlDateTime. For some really silly reason, this data type's MinValue method has not been expanded to use the new minimum date. Probably because no one at Microsoft even thought about adding a SqlDateTime2 type, or any of the others like SqlDate and SqlTime.
What I had to do is find the code in my data access library that used SqlDateTime.MinValue to check dates before sending them to the database and changed it to use DateTime.MinValue. That will use the proper minimum date.
Do be sure and use DateTime2 in SQL or the database will be the next thing that will throw an error.
Hope this helps.