For the first sentence, do you intend to use past tense? Because "once too often" implies either past or future tense. I don't know if I've ever seen it used in present tense. That doesn't mean it's wrong, necessarily, so if anyone thinks otherwise, please let me know. If you mean to use past tense, I recommend using "watched" instead of "watches". If you mean future tense, "will watch" may be better. As for the second sentence, it's grammatically correct and makes complete sense. Although, the typical phrase used for heating hands or other body parts is to "warm" the hands, not to "heat" them. Saying "to heat his hands" makes sense, but "to warm his hands" sounds more natural. The third sentence sounds great! It seems natural, makes sense, and looks wonderful overall. I hope I didn't confuse you at all.

Probably 'Tom used to watch tv too often' ? Second - 'He went to the fire (approached fire) to warm his hands'. And last one is spot on. The problem is when you work on sentences without given context it's quite difficult to guess what author wanted to say and meaning becomes very subjective (that's my impression from the times when I used to learn English anyway, teacher would give you a list of random sentences and off you go :0). Вы хорошо сделали!