Fall dormancy pruning on Annabelle Hydrangea is the way to go. It blooms on new wood so you'll still get flowers in the Spring. Same for Buddleia - wait for fall dormancy. Fall is the best season to transplant so go for it.

the RHS advice for Annabel which is a P arborescens is as follows
'•Hydrangea paniculata and H. arborescens are treated differently to the lace cap types. Although the only essential work is to remove dead wood in spring, these species flower more prolifically when pruned back annually to a framework of branches. Each spring, cut back last year’s stems to a pair of healthy buds to maintain a permanent framework. To produce larger flower panicles on strong, upright branches, hard prune to the lowest pair of healthy buds, creating a low framework of branches. This usually results in a pruned framework of no more than 25cm (10in) high but, if more height is required, cut to about 60cm (2ft) tall.'

by all means prune it back to move it but don't remove too much wood as a hard winter will destroy the top most buds.
the same is true for the buddleia, but this is tougher than Annabel and can withstand harsher winters.

the soil is still warm and moist so go for it. keep as much soil around the roots that you can safely lift without hurting your back.