I have a couple of ideas here.
1) For the 1-wire connection, maybe use a flat telephone cable wire (or CAT5) and remove the outer covering, exposing just the internal wires and their own sheathing. That way you would have 2 very small diameter wires going through the door seal. I can't believe that this would break the seal.
2) I monitor my hot tub temperature to sense when it drops below a expected minimum - below which, I know that the heater isn't functioning. I suspect that a freezer would have the same approach. If the temp gets higher than the 'normal' temperature swing, then let HS raise an alarm condition. I have mine set a flag, speak every 10 minutes through TTS, and send me an email with the readings until fixed.
3) Again for my hot tub, I wired a DS1820 to a cat5 cable and then encased in a rubber coating that is used to dip tool handles in. I have used this successfully for a couple of years - both in my hot tub and in the lake where I monitor the lake water temperature. It waterproofs it, and also provides good conductivity. It costs only $14 (Canadian) and a 15 ounce can lasts forever! You can find it
here . Don't buy the spray, but the can where you 'dip' whatever you want covered. The spray takes too many coats!