Our neighbours promised last year they would get their huge fir tree
cut back. It is on the boundary and takes a lot of our sun in the
evening. As they havent had it done yet and we desperately want as
much sun as poss this summer would it be ok for us to suggest having
it cut back now (we offer to pay half)?

Ive read everywhere that winter is best time but would we be damaging
the tree and its potential health by cutting back now?

Many thanks for your thoughts.
Beccie