... Your insurance will cover you if you get drunk as a skunk and hit a busload of nuns while running a red light at 90mph.
People say this, but it's not necessary true. Many/most personal liability policies exclude coverage for acts of Gross Negligence. Drunk driving appears to be well established as Gross Negligence. And from what I've found, so is overloading a trailer.
My understanding of Gross Negligence is that one knows what they are doing is considered wrong, but they do it anyway.
Not an attorney either, I could be 100% talking out my ass, and I did not stay at a Holiday Inn last night.