Bibs and a coat are more versatile , but they can be a bit "drafty" where they separate . They do have the advantage of being worn separately if temps climb , but I don't think that will be a problem where you're going . They are generally more expensive to buy than coveralls .

Coveralls are more restrictive unless you do like me and get them a size larger and/or taller , but you won't have a cold breeze suddenly catch you by surprise . My normal clothes are large , but when buying coveralls I get XL tall , this ensures that I have plenty of room and even some extra space in case I have to layer under them . Of equal importance will be your footwear , don't skimp on the insulation there and don't lace them tightly while on stand to avoid cutting down your blood circulation . Cold feet can drive me off stand faster than anything else .