Ok so the problem is not the cage temp. It sounds plenty warm to me, maybe even a tad too warm. The outside temps shouldn't have any affect on his digestion unless he is exposed to them.
I would wait about 2 weeks before you offer him food again. This will give the digestive lining a chance to recover as regurging can be pretty stressful to an animal. Maybe start with a small gecko before you go back to pinks. I don't think you need to worry about him not switching back to rodents later. You should be able to find a few geckos in the next few weeks if you can find some trash piles to flip. If this doesn't work I am out of ideas other than finding a replacement.