now is as good a time as any, before new growth starts. assuming you want to re plant them that is. take as much of the root ball and soil as you can per plant. prepare the new planting spaces first, biggest hole you can for them, providing ground not frozen solid. Then water well and regularly until they are growing away freely. A light trim wont hurt them but dont cut back into old wood.
Hope this helps.

I think you might have difficulty moving lavenders, Charnwood, if they are established. I know this isn't going to be very helpful in your situation, but taking cuttings in the growing season, and planting them out as new plants would probably have been more successful. Make sure you take as much soil with the rootball as possible.

Agree with the above but add that Lavender like poor dry soil and Box rich and moist, so you should certainly also add in compost and a feed to amend the soil.

Thanks for advice they are only a year old so will move
them this weekend.