Moving Herbs

All 3 are susceptible to a hard frost. I've lost a few thyme and rosemary that way. So if the new site is exposed, they will need some protection if a cold spell is forecast. Our bay is well established now, a few years back a frost of -17C killed it off above ground but in the spring, new shoots appeared from the roots. A younger tree would not have survived. Best time to move would be as tomanytommytoes says with the least disturbance to the roots as possible: have the destination site well prepared, dig up the herbs with as much root as possible, transport to site, plant and water in well.