Having completed the 2022 winter RASA and previously a couple of the shorter events my reflection are the following:
Clothing: Make sure that you have proper winter gear. The cold that experiences during the early mornings and bad weather events is often underestimated. There were times that i was riding with every piece oof clothing I had. Cold weather of this nature leads easily to getting sick (which i did) and results in probably the greatest number of withdrawals.
Make sure you have enough non-cycling warm clothing for the support stations and to sleep in. It also helps to have some form of warm slippers or lite shoes, thick heavy socks etc.
Footwear: I used the Shimano XM9 which provided great support on portages but more importantly kept my relatively dry during muddy crossings and some water crossing. Cycling partners in shoes constantly had water getting into their shoes.
I carried two sets of riding gear with extra socks.
Gloves: Buy the best winter waterproof gloves you can find. Having frozen hands makes using your fingers for brakes, gears, eating, clipping bags open etc difficult.
Navigation: Learn how to read a topographic map and what the legend items are. Knowing exactly where you are based on physical objects around you is vital. Learn how to use a compass and to orientate a map. There are numerous occasions when one is not on a road just walking through open terrain. It helps to know the bearing.
Food: Eat real food. Make sandwiches at the support stations and take fruit along. Most support stations have adequate supply. Gels and high energy bars become unpalatable very quickly.
Water: I used two 750ml water bottles and this was adequate. I only drank water and used juice and Oros from the support stations to supplement. Most SS had coke to purchase.
Budget: R100 / day seemed to work for me. Included washing and cokes.