Another view...

If it's a rental, are you able to paint?

No one? :-(

Is the green rug staying?

I personally would go with an off white, cream color. What furniture (fabric, wood) will you have? I'd consider adding a piece painted red.

Also, hard to see, but how nice is that chair rail? If it's nothing special, I'd consider removing it.

A couple more questions:

It's a "country rental". Can you explain what that means?

How do you want to FEEL when you're in the room? Cozy? Beachy? Airy? Warm? Cool? Rustic? Austere?

What do your furnishings consist of in terms of fabric and color and wood type?

"I just want that warm, homey, country feel."

The only potential issue I see with red and green is to stay away from a Christmasy color scheme.

Oops, how did I miss the warm, homey country feel thing?

Sorry.

If that were my room, I'd get some paintable wall paper in a simple design to put up under the chair rail, and I'd pain that a woodsy, warm brown, something like BM Middlebury Brown.

Example of paintable wallpaper:

I'd paint the chair rail and crown trim in a mocha;

Then I'd paint the top half of that wall in a cream.

I like the idea of a warm tan, which is what I have in my home. IMO, off white/ivory is sort of passe', since Navajo White was used by every builder probably close to 10 years ago.

My sis has a rust with a deep tan LR/DR, very close to what's in the second pic, and it has a very country look and feel. IMO, both colors would go well with the rug.