I haven't toured since as lot of the new gear has come out but if I were to do it now, I'd back a pair of wind block tights without chamois and one or more pairs of Capilene or REI equivalent thermal underwear to wear over my shorts and under my tights. (I do that commuting and on winter rides.) Thermal tights seem to me to be a waste space and cost-wise whereas thinner tights pack better and the separate inner layers offer far more versatility.
Ben