I’ve been there done that but it was on the monkey bars in grade school when the outside temperature was close to zero. I did it on my own just because I was such a curious sort and had to see what would happen. I don’t remember how I got unstuck but it couldn’t have been very traumatic else I would have remembered the unsticking part. I think I may have just continued to breathe out on the pipe until it warmed up enough to thaw my tongue loose. This all occurred in North Dakota of all places and there was one thing I was familiar with was cold weather.
You could wrap your hands around the pole/your tongue to warm up that section of the pole too.