Tall tank heating question.

So I have a quick question if anyone has a solution to this issue. My corn is doing fantastic, first time snake owner he is about a year and a half now and such a sweet snake couldn't be more happy with his personality. My concern really is with temp. He is in a 75 gallon tank. I love him in a large tank because he can stretch out and climb all over. The issue is how to really get heat down that low consistently. I have 2 large heat mats on the bottom of the tank for him, he knows his hot and cold spots but getting that true basking temp for him sometimes is tough down low because the lamps don't push heat that that far even with high wattage reptile bulbs. I have a ceramic heater over his side that kicks on at night for him but since his tank is in my finished basement , it gets chilly down there. Should I be too concerned with this? He is obviously finding heat with the heat mats and I see him occasionally at night up on the top branch curled up under the ceramic heat lamp. Anyone have this issue with larger tank set ups?

It looks good! It sounds like you have it set up well. If he was getting too cold, he wouldn't be digesting his food. So as long as he's digesting well and not having any regurges, he's getting enough heat. They only really need about 85ish degrees to digest easily.