Got basically all my hair back - how long can I expect to maintain?

[Woodyy]

At the start of the year I never thought I'd be writing this but I just had that moment where I looked in the mirror and thought to myself that my hair is basically back. Except for maybe 1cm of recession at one temple I've regrown my hairline completely and restored 75/80% density. I am more than happy with this considering I've only been on fin for about 8 months. It's been very slow but steady progress I think, I never noticed day to day or even week to week improvements, it all happened so slowly that I never noticed it was happening at all.

Anyway, I'm basically just wondering statistically how long can I expect to maintain on finasteride for now? This is all I use so I don't have to worry about what some people report about the longevity of effectiveness in other treatments such as minox.

Also, when/if the dreaded day does come when I start losing what I've regrown and there's still no advancement in treatments would moving onto dutasteride be a viable option?

Cheers