Problem BP. Is he OK?

I've had this BP for 6-7 years. He is my first snake. He's never been ill, but i have one problem - he never eats during winter. For up to 5 months typically from late September to early February he just doesn't eat. It doesn't seem temp related. It does get cold but i even got a second heat mat and thermostat for him to make sure that even the cold side doesn't get lower than ~82 during winter. When he does eat, he takes ~140g rats, usually taken every 10 days or so. At this time of year i usually get nervous because hes not eaten for a couple of months and probably won't for a couple more, so i decided to take a couple of pics and let you decide if there is anything i need to be nervous about.
https://s18.postimg.org/f5ih6ssd1/bp1.jpg
https://s18.postimg.org/jfx52dxg5/bp2.jpg

Honestly, from the pics you posted, it doesn't seem like there is anything to be concerned about. That snake looks big and healthy. If it is indeed a male, it is typical for them to go off feed when the weather starts to get cooler out.

If it's your sixth-seventh year with him you probably know his feedings habits, responses and personality. If he does this every year during winter and has passed without any problem, then there isn't anything major to worry about.
But anyways, the best thing you could do is keeping track of his body weight. You should make a calendar and weight the snake, you write it down and everytime you think it's necessary to weight him you do so. After you've done it for a while and he has not been eating, you can at least see and know how many grams he's been losing during the period, so you can keep track without having to guess only by watching at him.
Don't worry, keep on offering food and good luck ^^

He appears healthy and a good weight. Winter time fasts are not unusual for adults, especially males. My experience has been the older they get, the longer the fast lasts. I've got 2.0 23 year olds that eat about 4-5 months of the year. Once the fasting starts, I only offer food about once a month until they start again.