I tend to do layers at those temps. The bottom half is more difficult. I might wear regular shorts under my tights and bring knee warmers for later. That tail rider will hold it all! I'd also go with my lighter weight full finger gloves with wool liners at first. Definitely toe covers. For the top, I'd do a SS jersey with a short sleeve base layer, arm warmers, and a jacket. That way, I could peel stuff off. I don't do well well in LS when it's 65.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport