I see between 190 - 210. All varies depending on ambient temperature, drive conditions, whether the cooling fan is on or off, airflow from freeway driving, how heavy your foot is on the accelerator, and how much weight you have in the van.
The idea is to regulate the engine and transmission temperatures to stay above 150. I've heard that 150 is the magic number for open loop / closed loop operation, and learning/relearning drive cycle. I could be wrong, but I've also heard the number 100 Celsius or 212 Fahrenheit as acceptable operating temperatures. I've also heard that with modern transmissions, anything below 225 is fine, and that the temperature that you don't want to exceed for any duration is 250.
Most OEM thermostats are around 180 or 190. Engine coolant flows completely through the cooling system. The transmission has a cooler bypass valve, which closes about 180 or 190. Transmission fluid now travels to the heat exchanger. In theory, the cooled radiator fluid brings down the temperature of the transmission fluid via the oil-to-water heat exchanger. In the Transit Connect, it's a little finned device bolted on top ot the transmission. Air flow and the fan, plus the radiator fluid, work together to cool the transmission fluid. In a lot of trucks, transmission fluid is passed through the cool side of the radiator, which is a similar cooling method. In some trucks, the transmission fluid then routes through an oil-to-air auxiliary cooler.
Learn to trust & believe the electric scan gauge reading for transmission fluid temperature. It's the same number which the car's computer uses. Any other temperatures you read, from any gauges you install yourself, will be less relevant.
Consider that the temperature sensor inside of the transmission is suppose to be a pan temperature. Much hotter fluid is in the torque converter, pumped out through the cooling line, then returns to the transmission. Cooling line temperature is much higher than pan temperature. Return line temperature is lower. Which makes the pan temperature somewhere in the middle of the the hottest & coolest. In larger transmissions with more fluid capacity, I've heard that the temperatures can vary even more, depending on where you are taking readings. You can drive yourself crazy with setting up gauges and temperature probes. Get a "point & shoot" thermometer, and you will really go nuts. Temperature of fluid inside of the transmission lines, and inside of the transmission case, is not the same as whatever the thermometer reads when you point & shoot the outside of the transmission case, pan, lines, cooler, & fins. Imagine pointing that laser thermometer at a BBQ, then pointing it at the meat on the grill, and then taking a reading by pointing the laser dot at the pile of hot coals.