Don't see new buds down low
I read to cut one year old clematis back to 8-18" being sure you have two sets of healthy buds.
In both cases the buds even at 2-3 feet look small and possibly dry, certainly no growth. There is green growth several feet up in fact one of them has flowers way up high now!
Should I go ahead and cut them way back and expect those buds to fatten up and do their thing?