Depends on how long you want to take them out. A couple towers or a substation is easy to replace, they will have a temporary tower up in a few hours. They have this ability because a tornado could take out a few towers. Likewise substations fail once in a while.

If you take out one wind turbine: they break often enough that it doesn't matter. They assume a few will break for mechanical reasons and that is accounted for, it hurts profits a little but probably less than their worst case failure budget has planned for. They will fix it sometime in the next few years. If you take out a lot of wind turbines, things get hard, replacing each one will take time: factories are generally booked months in advance and crews that can do this job is also not readily available.

Don't forget though that everything you do creates an effect. Take our wind turbines and they will beef up security. You are taking the risk that they notice your activities and put in some security system that catches you.