As mentioned by others, everyone is different (and your dose is much higher than mine). I've been at 7.5mg per day for a few years and am only chiming in due to having given up alcohol this year. I haven't seen a tangible change in my INR pre- and post-drinking but, of course, YMMV. I've also been on the wagon for only five months although I would think that would be plenty of time for a trend to appear (testing weekly).I have had to take what I think is a shocking amount of warfarin for almost 3 years now, about 102 mg a week on average. Its shot up to 115 a few times and been as low as 95. What compelled me to post this though, is I decided to stop all alcohol about 5 weeks ago now, and expected that might cause my warfarin need to climb a bit. It's jumped to taking 107.5 and my inr has dropped to 1.4. So I am nudging it up to 17.5 3 days in a row and 15 the rest of the week to see what that does. Testing 1x a week.
I stopped the alcohol because I want to lose weight and get off bp meds and also start running more. I am down 7 lbs and already stopped the bp meds. I'm not touching the alcohol until I am down about 15 lbs.
I'm an organic gardener and landscape nerd so spend a lot of time outside in the heat. One too many trips to the ER for tachy convinced me to finally give up those post-lawnmowing beers (and those I'd have for any other excuse). Being a homebrewer, that hurt on many levels but my cardiologist was overjoyed that I'd taken alcohol out of the health equation. Alcohol is obviously a cardiac stresser and at my age it was an unneeded demand to place on my heart.
Good luck with your weight loss and reducing your medication needs, it's a journey but one worth taking.