+1 on merino - have done my 20 mile journey with M&S wool trousers, merino base, work shirt, gore wind stopper and merino gloves with no problems (temp range needs to be around 4 oC~12 oC) - also have a pair of Vulpine bike trousers which are excellent - my aim is to de-lycra the look where possible. Having to change to use the bike is not my ideal unless on a tour, but also admit I am mainly a fair weather bike commuter. The wind stopper can shed the arms so expect can be used up to 15 oC~16 oC and this will cover 70% of SE England typical morning/evening temperatures - although this winter may force a recalibration! I aim for around 150 miles per week on the commute, this winter more like 60 mile average, so the car is doing more mileage than I would like.