are you opposed to having a split across each span? likely will save money, even if you do find one long enough.
see if you find one you like, go and look a few places, and reach out directly to the manufacturer. i've been pleasantly surprised with the information i've gotten from them about this.
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not inexpensive but costco has a deal with sunsetters for 20% off. here are their prices, and they go up to 12'
actually looks like they are 20% off right now from their site: https://www.sunsetter.com/c/easyshades/manual-easyshades/
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actually, this company sells what you probably need, in widths up to what you are looking for for ~650 per shade if it's 13' x 3x
https://www.maantaoutdoor.com/exterior-roller-shades/14367-reef-roll-custom.html
they have cable guides, which is important for what you need since it isn't going all the way down