Planning a local Gemma 4 build: Is a single RTX 3090 good enough?

Hey everyone. I am planning a local build to run the new Gemma 4 large variants, specifically the 31B Dense and the 26B MoE models. I am looking at getting a single used RTX 3090 because of the 24GB of VRAM and high memory bandwidth, but I want to make sure it will actually handle these models well before I spend the money. I know the 31B Dense model needs about 16GB of VRAM when quantised to 4-bit. That leaves some room for the context cache, but I am worried about hitting the 24GB limit if I try to push the context window too far.