Ahoy Peter,
The following is only one man's opinion. There are many variables to your inquiry. Most importantly; Are you using roller furling or not? Are you thinking "locally" or globally"?
First, I would like to redefine some sail terms. Lets call the "original' W-32 headsail of about 177 sq ft, the Working Jib. It is not a full hoist sail. The original Yankee was about 254 sq ft. Yankee's are full hoist sails. My Yankee is 305 sq ft. The "Super" Yankee, as popularized by Kern was about 350 sq ft. A Genoa for the W-32 would be about 440 sq ft (+or-). A Drifter, of about 1 1/2 ounce material, would be about 450 sq ft and above.
You should have at least 2 headsails - not counting the Staysail or Storm sails. I have roller furling and 4 headsails plus Spinnakers. I use my Working Jib, and Drifter, by far, the most. That said, if I only had one headsail it would be the regular Yankee. Furling up a big sail to make it smaller is common and can be done but is not usually the best way to go. I play the percentages with my headsail choices. As an example: I headed to the Marquesas with the Genoa on as there would be a high percentage of down wind work. I came home with the Working jib on as it would be a passage to weather. On one 4000 mile delivery of a W-32, I alternated between no headsail, a yankee, and a Drifter.
I just talked to Bill Andrews in Hawaii. He is a very good sailor and a singlehanded circumnavigator, which represents only part of his sailing on his W-32, Quest. He went around the world with only a Super Yankee and Drifter. In many instances the Super Yankee was too big.
Concerning your Mainsail. The loss of area should not be a detriment. Your area of 266 sq ft is about the same as a battenless Mainsail for the W-32, although the distribution of that area is different. In the old days, these sails were much more popular than they are today. I cruised over 30,000 miles with one. There is very little difference in performance and both have performance benefits.
I hope this has been of some help.
Dave