I usually proceed section by section. Strings have their given amount of the reverb I've chosen for my piece, woodwinds are their amount, brass have theirs, etc. The spatial simulation created (in part) by the reverb is very important in orchestral music, so I personally think that the first question you have to ask yourself is not “does this frequencies range need reverb” but “does this instrument section need more or less reverb” (according to your ears as well as according to logic), regardless of how this may impact the EQ.
Then, if you have issues with your EQs (let's say that your grand casa becomes completely drowned in its low-ends), you correct the signal sent to your reverb rather than the signal coming out of it. This is a matter of compensation. In the case of your grand casa, if you identify and turn down the low range that has been saturated by your reverb, it should get back to normal without neutralizing the actual reverb. The same thing goes with double basses, low brass, etc
I don't know if what I'm writing makes sense. I hope it does. It's 2:30 am here, I should probably go say hi to my pillow.