are the walls and ceiling the same? why does it look like smoke damage to ceiling? what are your thoughts on floor? I bet if you put in some neutral tile that would make a HUGE change

No smoke damage, just lighting with photography. Yes it’s all the same and I want to lighten it up

It’s so seamless, I’d leave it for now and try very light area rugs and furnishings first. I’m usually in the paint it camp, but in this case, it honestly looks right as is.

Check out Sarah Richardson's Chalet and Island series. She paints A LOT of wood. Might be just a wash on the walls would keep the character but tone down the brown a bit. You tube can be your friend if you want to see some dramatic changes. Bet she's not the only designer who has some work posted.

I'd paint the ceiling /walls white and replace/re or stain the floor. Would be way too red for me : ) More bothersome that the cedar, actually.

I think if it were my house I would do really large wall stencils, maybe after whitewashing first, but maybe not (I wouldn’t choose this color scheme, but something this oversized and folky in terms of a pattern

I think I might then stencil the floors in the same or a harmonious pattern as the walls, maybe in the same color, maybe in contrasting color, but I’d also use huge area rugs with lots of texture.

the reason I’d go for stenciling on the walls is how many knots you’ve got there. Stenciling will play well with the knots.

If those walls are a true rough sawn product it will not paint that great. You may want to have it sprayed and even then.