Wierd problem in cold weather

We were out in Syracuse NY about a month ago doing some college visits for my daughter. Well we spent a couple nights in a motel and the first night we had ice and about 2 inches of snow. So I hit the Auto A/C and let the car warm up inside. It was about 15 degrees out and this did not really do anything with the layer of ice on the windows and the inside was still cold. So I started the car and placed the front and rear defrosters on as well as brushed off the snow. I confirmed the car engine was running and went back inside for about 15 minutes. We come back out to leave and the car is off and when I opened the doors the dome lights were very dim and still cold. I pressed the start button and got all kinds of warning flashing across the dash. I turned the car off and then back on and still had warning flashing. With the car on the A/C fan seemed to be running slow and as mentioned, the interior dome lights were very dim. I put the car into reverse to see if it would back out of the parking spot and it moved, but still no engine running. I put it in drive and went across the parking lot and no engine running and the EV indicator was off. I pulled out on the main road and accelerated hard and the engine came on. At this point the warnings were Hybrid system failure and collision system failure. We proceeded to our scheduled college meetings and found a Toyota dealer when we were done. We pulled in and they plugged in to mind melt with the car. In the end they had no idea and reset to 20+ computers. The warnings were now all gone and we were on our way and have had no issues since.

Can anyone answer that if the front and rear defrosters are on high will the engine shut down when it reaches temp and allow the battery to be drained?

I spoke to me regular dealer where I bought the car and they said that this specific problem should happen and since the dealer in Syracuse cleared the faults in the computers, that they cannot help me.

A similar issue happened on my 2007 Pius and killed my battery doing the same thing when running the front and rear defrosters. Went outside and the cars engine was off and the battery was dead, except the car was warm inside on this one.

 

Sorry I did not have model in my profile. It is an 2017 Prime Premium.

Ice was running when I walked away. Both defroster indicators showed on.

Front and rear defroster were activated using buttons to the left of 11" touchscreen. ICE always runs when front defroster is activated this way in my understanding.

Key fob was in my pocket so maybe the immobilizer shut off the ICE, but the A/C fan was still blowing (a little slow) and cold air was coming out.

I do not know if the starting/auxiliary battery was actually low. I had no way to check. Interior lights were dim when doors were opened when we got into the car and defroster fan was running slow along with what seemed like every warning indicator was lit on the dash.

I had about 10 miles available on the hybrid battery when I parked it the night before and the same 10 miles after all this warm up time with defrosters. Seemed like no energy was used from the hybrid batteries, which I though that when I first used the A/C button on the remote it would have engaged the heat pump to start heating the car and depleted some of my charge.

Point of the 2007 Prius story, was that I had a similar situation where it also shut down and drained battery completely after starting and putting on defrosters.

 

Pressed the start button, turned on both front and rear defrosters, went back inside where is was warm. Did not look at what mode it was in.

Prime was left in charge mode. The last few miles in the interstate highway before we got to the hotel, I put it into charge mode which is why I had 10 miles left on EV battery. I do not remember changing to EV or HV. I will have to check to see what happens when you shut it off in charge mode and then restart vehicle to see what mode it is in. It was the first time I had used the charge mode.

It was not plugged in. No accessible charge points.