I do grow a few spiderworts (Tradescantia) here so they should overwinter for you. IMO, they tend to get brown spots and melt after they bloom. I think they do better here when the roots are kept a little cooler - they don't totally melt away. 'Sweet Kate' is in my sunny bed but doesn't get direct sun but it does get hot there. It melts away to nothing. I have 'Osprey' where the roots are definitely shaded by a hosta and it gets a few hours of direct sun in the afternoon. It doesn't melt away as totally as 'Sweet Kate'. Maybe morning sun would be better for these but I don't have any. If you deadhead them, you'll get more blooms.
