For the heat source of your enclosure, put a plastic shoe box full of water on top of a heat pad. Then set up an aquarium air pump external to the enclosure with a hose that leads into the enclosure into the heated water. The heated water will keep the humidity higher and the aquarium air pump will keep the environment full of fresh air. Keep the nest site dry. Ventilation of the enclosure can be kept to a minimum as that the air pump will force the fresh air in.
Nights will be fine if they dip into the 70s external to the nest site. Day time highs external to the nest site are good in the low to mid 80Fs.
The eggs, if good, are likely to hatch on their own in 49 to 50 days.