The manual for any car (usually at the end of the manual) provides tabular data on the maximum possible weight of the towed trailer. In this case, the trailer equipped with a brake system, the maximum allowable weight limit for towing more. Such data about the car is quite common and if you do not have an operating manual, you can find it on specialized online forums dedicated to a specific car model.
There is also a good English site //www.whattowcar.com/, where by scoring a bunch of parameters on the tractor and the trailer, you can quite accurately select one to the other.
It is also worth noting that, according to the rules of the road, the BE category is not required if the maximum mass of the trailer and the maximum mass of the tractor does not exceed 3500 kg in total, and the maximum mass of the trailer must be less than the curb weight of your car.
Choosing a car-tractor for a heavy trailer, it is worthwhile to give preference to a diesel engine as more economical and high-torque.
When operating a train on the territory of our vast, including and in winter, preference is given to all-wheel drive.