How long would it realistically take for me to pass 漢字検定１級 ?

For some much needed context for anyone to be able to answer this kind of question, here is some of my background.

- I have been learning Japanese for around 3.5 years, passed JLPT N2 with a good score, and plan on taking N1 in December this year.

- I live and work in Japan, I have an office job that requires me to use almost exclusively Japanese every day since all of my coworkers are Japanese and can't speak English, and a lot of my work has to do more with environmental/community development as opposed to translation or interpretation. Some of my job does revolve around being the designated English speaker but the majority of it does not.

- I am taking the 漢字検定３級 in October, I expect to do fairly well. I know about 60% of the kanji in the test already, and I still have a good amount of time to drill things. I consider myself quite good at rote memorization and I find it very fun, which is what has drawn me to 漢検 in the first place.

I'm not talking about magically being able to whip through all the required levels; I don't even have every 常用 kanji memorized yet and I understand that I have quite some time left to work before this is at all within reach. But I do feel like this is an attainable goal for myself in the not-so-distant future, seeing as it is something I have a genuine interest and find enjoyment in. More than anything I am just asking people who have experience with higher 漢検 levels what their studying timeline has looked like and how I could expect that to look for myself. １級 is not to be taken lightly, and ２級/準１級 aren't either, but this is something I can seriously see myself dedicating a lot of time and effort to over the next few years.