Do not use warm or hot water. You will not have windows if you do.
Hair dryer or heat gun or park some place warm.
Some 3x5 cards between the glass and seal. Spray dry silicone lube and let it sit for a bit.
Take door cards out and spray some wd40 or other oil or silicone lube on all the joints and the lock areas too.
Moisture gets in there and freezes. Common issue.
Solution is keeping moisture out of the joints and mechanics
A guy that worked with my brother, had quite a commute to get to work, from Williamsport PA to wellsboro PA which is about an hour+. He had a gasser Jetta with an automatic, worst of the vw world. About half way to work his driver window fell into the door. He knew I tinkered with vw’s and so he had my brother call me.
My first question was “is he a smoker?” Yup. The first thing smokers do when they get in a car is crack the window about an inch, which is not a problem 350 days out of the year, but after hitting that down button so many times with the window iced closed the mechanism that holds the window came off the bottom of the window and traveled to the bottom of the door and set there. After driving for 30-45 minutes with the heat on the window came loose and fell. His ride was cold the rest of the way into work.
I told him how to fix it, I think I even walked him through getting the glass back into place and wedging it so he could drive home in comfort.
The point is if you drive it long enough the heat will melt the ice and the window will work once again. Provided the mechanism is still attached to the glass and hasn’t come loose.
If you garage your car, put a heater in the garage.
If not, there are small heaters that you could place IN your car. Something like a 1500 watt ceramic... Make sure you place it appropriately, with some protection around it to keep it from coming in direct contact with your vinyl/plastic/leather. (A few small pieces of plywood?)
Run the heat, melt the interior mechanism ice. Then apply the WD-40 or other moisture displacement spray. Work that window to get it lubricated.
I have a 2013 beetle with frameless windows. A few years ago, it rained on the way home, then dropped into the 20s the next morning. I had to climb in through the hatch to get to work. By the time i drove to work (35 minutes) with the heat on full blast the windows worked. I have put towels on the windows and eased the widows up against the seal to prevent freezing. I park under a metal awning so I don’t have to worry about rain/snow getting in the car.