Stain Spill

While staining my deck with Defy Extreme Semi Transparent Butternut, I accidentally stepped on the corner of the tray right after filling it up. I've fixed the overspill on the deck floorboards, but now I need to fix the splash on the wall of my house(Please see picture). The house is cedar and was stained about 2 1/2 years ago with SW Woodscapes 7067 Cityscape, which is solid.(I've attached pictures of this original house stain) That wall gets some intense sun during part of the day, so I'm worried I'll need to re-stain the whole wall because the original color may have faded(?), which shouldn't be so bad. My question is: To fix this mess, can I:
1) Just stain over the splash with the original SW stain(I still have a couple gallons left), or
2) will I need to sand the entire wall and start over? or
3) just sand the area where the splash is and re-stain?

Thanks.