I would wait until it warms up a bit. Mine are not showing any new growth yet

I dont usually do mine till april then only down to the first pair of buds. If they get to big I trim out 1/3 of the stems over a 3 yr period.

Perfect answer Sbg. That is the advice I give my customers.

Thanks. not that clear as my hubby has said 'will they realise you mean the first ones from the tip rather than the first ones from the ground?' grrr.
first ones from the tip just to clarify.