Do you need drapes ? This is not a door for access to the lake so maybe explain what you need form the drapes like privacy , heat and UV control etc. That size of window will need to have at least a center support if you go wrough iron or larger type wood dowe for the rod.Depending on your style makbe this type of drapery look

Beautiful view! Here is a 240" rod from Home Depot available in different finishes. The 1 1/2" diameter isn't bad but personally, I would prefer a larger diameter and would look for possible combinations using several sets or sections that can be connected. So, for example, instead of one 20' drapery rod set, consider how to connect two 10' sets at the center bracket. You can use the leftover sections for other windows and remember, you can change/add finials. Or, if you're a DIY'er, you can look at using wood dowels and connecting them with wood dowel connector screws.

I hope your drapes are longer than 96" so you can hang them well above the window. While that wall is open, ask your contractor to add blocking above and beyond the sides of the header so when you hang your drapes, the hardware is affixed to wood instead of drywall.

Other options are to get custom made of course - there are online stores, some fabric stores that make custom drapes can provide the hardware, or an interior designer can tap resources.

Home Depot 240 inch Rod

I have a Kontur Traverse Rod (from curtainrodconnection) for my large picture window. Mine came in 2 sections (wall support, but traverse rod doesn't stop at the supports), yours would need to be in 3 sections. I operate mine twice a day, absolutely perfect 2 years later. Yes, yours would be $500+ BUT they are of great quality. I put them up by myself and have lined linen drapes on them.

Thank you all so much!! I have some good ideas and I’m excited to research.