If this is a cabin you plan on keeping for life go bigger....you will not regret it. I've never heard anyone say they wish they went smaller.
I built a 1800 sqft cabin, 30x40 main floor and a loft. 1 bed/bath dwnstair and 1 bed/bath in the loft. It was great for a family of 4....Then what happened? Kids grew up got married and both had 2 kids each. We all like spending xmas and holidays there an it gets a little cramped with extra blow up beds in the way.
Or another option is to build small but build in such a way that bedrooms can be added on easily.
If you have the financial means and ability. I don't think you would feel negative about being on the larger side. I would say if you do build on the small side have a plan to possible add on and make it simple.