@fietsbob: Sorry I meant both.
@djb: We always use booties they do help alot. We also use them in the morning when the grass is very wet at the campings so our shoes don't get wet. We even have thick winter booties for when we do day rides in the middle of winter. But the temperature has to be around freezing else our feet sweat.
@Newspaperguy: We do the same, but do carry leg warmers (like very thick stockings without feet) that can be put on/off very quickly. They are also great in the mornings when it's very cool.