Wasn't a breeding issue, its a husbandry issue. Since I've already expressed my views I will try and help your problem.

Why don't you get either a few pieces of flexwatt or you can buy those expensive Zoomeds pads. I would personally go for all UTHeating, because 55g are 18 or 24" high? You really don't need to bother heating all that dead air if the snake lives on the substrate.

If I were doing it I would have 2 separate heating pads (either strip of flexwatt or heat pad) on 1 Thermostat, both running cool side temps of 80-84 degrees. Put on a the cold side and one in the middle.

Add a third heating pad and have it on a separate T-stat and have it on one side around 90-95 degrees.

That would give you your heat gradient and won't destroy your humidity.

Then I would also consider separating your snakes, since they get no benefit to living with other snakes, and only get the negatives of living with other snakes.