Hello Ben,
Welcome to our group. First off, what I say is my opinion only. The use of sails and their configurations is often debatable. I will not get into those debates with this post. The following works for me though, and admittedly, I only follow my own advise bout 85% of the time. What I do on a narrow river is not always what I do in the ocean. The following regards going to weather:
I suggest a much smaller headsail than a SuperYankee, which is about 350 sq ft. I suggest something like the original "Working Jib", which is 177 sq ft and is 8 ft short on the hoist. This is my most used headsail. Even when furled a bit, the shape will be better than a furled Super Yankee. I use a Staysail on a boom with a traveller. It is reefable and would definitely be reefed in the conditions you describe. In 25k I may be using my Storm jib hanked on on the inner stay, above the furled Staysail. This Storm jib is about the size of a Staysail that was double reefed. I use this more often than most Westsailors would believe. It will sheet to one of the same locations as the Working jib. Note: The Working jib is still flying though it may be furled a bit.
The Main is reefed, possibly double reefed. With my sliding gooseneck, I would be positioning it in a lower position. This is about 1 ft lower than the normal position. The Main is not sheeted in tight.
So, in 25k I would probably have a slightly furled Working jib, a reefed Staysail, and a double reefed Main. I would also be about 15 degrees further off the wind than on smooth water. I would be enough off the wind to keep up a good speed. I would not be dragging a rail though.
I have asked Jay to post some pictures this evening. Stay tuned. The 1st picture was in about 20k. Notice a full Working jib, full Staysail, and single reefed Main. The boat is definitely standing up better because of the guys on the rail. Boat speed is 6 1/2k The 2nd sailing picture shows a single reefed Main, single reefed Staysail and about 40% of a regular, 300 sq ft Yankee. The wind is about 20k but the boat is boogeying its way through.
Off topic but important is the bottom of the boat. I suggest that you fair the hull to the rudder. if you can swing the costs ( about $700 in materials). A complete fairing job in the stern and a feathering prop is worth more than 1k at the lower speeds and 1/2k average at cruising speeds. More speed is more speed to weather. There is some info on the forum about this.
But MOST important of all is the New Years day sail. I can not tell you what will happen if you don't sail because I don't know. I always sail. It is tradition.
Good luck, Keep us informed. Dave