Audi 80 Coolant Temp: Use Winter Thermostat?

Hello everyone.

I recently acquired an Audi 80 B4 from 1994 with a 1Z engine to use as my winter vehicle.
I've noticed that the thermostat isn't closing properly, and the engine only gets warm when driving on the highway. The parts supplier said they have three different options available: 85, 90, and 95 degrees.
"Does anyone know what the normal thermostat temperature is for a 1Z engine? I think it's probably the same for all 1Z models. Is it a good idea to use a 95-degree thermostat for the winter, or is that just unnecessary?"

Okay, I also have a 1Z TDI engine from Audi, also manufactured in 1994. I replaced the thermostat about two years ago.
Also meiner geht bis 90°(im Sommer) und dann wird halt geregelt. So richtig Warm wird meiner (im winter)auch nicht bei normaler Fahrweise ca 100km/h, außen schweine kalt und die Heitung schön aufgedreht. Geblow level 3.
It's always been like that. The only thing that helps on short distances is to place something in front of the radiator. Then it will reach 90° and stay there.

Thank you for your answer, Tom.

That's right. It will never get warm. Yesterday, I tried clamping the hose to the radiator with a clamp, and even after 20 km on the highway at 120 km/h, it didn't get warmer than 95 degrees. The clamp sealed completely, because afterwards the hose was completely cold. I will leave the clamp on during the winter .

The original temperature is 87°C. According to the AI, this will increase to 88°C in winter, and to 90°C on the highway.