I only have a 10 mile trip (no highway 45 mph top speed) to get the boat to the lake, but the 19 footer with tandem axle steel trailer is right at the 4500 lb. limit. About a dozen trips per year, 2 people in vehicle.
I wouldn’t even think twice about it. I tow every day practically, and I worry very little about being on the edge of towing capability. Best advice is to give plenty of room for breaking… which is my rule regardless