Snbtwins, your best bet is decide the length of the rod, where you want the panels to start and stop. Since you are having the panels custom made, I would suggest you use that measurement to figure how many lengths or half lengths of fabric you want the panels to be. When I make panels I prefer them to be at least double the width they were cover. Since you will not be closing them, that would be from the edge inside edge of the window trim to the finial. Measure from arrow to arrow and double (or 2.5 times) to get width of finished panel.

You could remodel that hearth and do away with the part near the window :) I like the idea of hanging the panel on the left side of the window and just living with the weird drape over the mantel when they are closed. But I think I would put up a ceiling height valence and do wood blinds. You can change the fabric of the valence as you wish to change the look and the wood blinds are gorgeous and give a room a nice feeling.if you are worried about the height of the blinds then do the top up/down honeycomb ones in a similar color to the walls to make them visually smaller. The window will still be the star of the show and the valence will be the supporting cast that draws the eye.

Pull the sofa off the window wall and center it to the fireplace wall itself. right now it looks like someone shoved it against the wall... Then add a sofa table behind it with some decor. take the tv OFF THE FIREPLACE.. and mount it to the wall across from the big window wall. take down the orange/brown curtains they really dont go. Limewash or whitewash the fireplace and add a nice mantel. You could also afford to pull the sofa away from the fireplace wall add an area rug. Here is my kinda sorta pic for you...

The not reason it concerns me, well not concern lol! But... is because it’s the front of the house. You can beef up the trim but there’s not a lot a room between each window. Do you want to add a window on each side of the three you have. Will that be too much? I was initially thinking just keep it and add some lights up there and maybe planters to the window sills. But it’s a hard spot to get to. Maybe fake flowers? Vines? Hard to tell the style of the house also. So if this is MCM , well uh that wouldn’t work. I’m thinking it’s farmy casual , chill vibes. And that’s why I suggested the above. What do you think?