Correct on Ficus benjamina not always sprouting on bare wood so I would not go right to that red line. I'd try chopping all the branches back to a single healthy leaf first. Often that makes the tree grow some new buds on the older, bare sections and you can chop back further next year. Fingers crossed that there are still some dormant buds in the section below your cut line.
Obviously dead branches can be cut any time.
All trees will respond to pruning better when they are healthy and happy so make sure your tree has been fertilised well for a few months before pruning.
Ficus are tropical so recover much better to pruning and repotting when they are actively growing, which is late Spring and Summer. Hard pruning in Winter will not give best results unless you have some sort of heated area with grow lights to keep the tree active through Winter.