I think raw vegans do incorporate some seasonal eating just due to the fact that certain foods become unavailable in the winter - like fresh berries.

Some might rely more on greens and sprouts(that they grow at home even) in the winter.

I try to stock up on frozen fruits for smoothies, but other than that I still eat a lot of greens, avocados, and tomatoes.

Angela and Matt have some yummy alternatives on their websites like sea spaghetti, flax crackers, and raw dried hummus http://www.rawveganbooks.com/index.php?cPath=100150_100148&osCsid=ef037cec23dacde1dc068b22e2e1faae .