The best answer is to let what happens, happen. Do not try to remedy that which is not known before it happens. What will be left will be left. The damage probably will be less than you expect. Plants will self-prune in this situation. Let them decide what has died back and what hasn't. Sit tight and wait, prune later.
hortster

Beigestonehill,
Why can't you water them?

you are trying to love them to death ...

i agree with leaving them alone ... what will be.. will be ....

ken

Why can't you water them?

A friend in Maryland (a state that abuts VA on the map) reports there's been no meaningful rain. I'm sure there are water restrictions, either mandatory or strongly recommended, until the situation eases.

You're sure there are water restrictions, did you check?
Surface drought is different than groundwater levels, which are fine from previous years' rainfall amounts. Most of Virginia is normal to above normal.* If you have a well you can help your plants in order of value to you, by drip irrigation, without taxing your well. Put your hose on a slow leak, like a leaky faucet - for a day or so, under your plant, until it's well soaked. Make sure you don't forget about it. Watering is an art, to be learned through trial and error. If plants are on a slope, hose leak dripping distance, from the plant, must be appropriate so that the downward flow doesn't runoff past the plant.

Here is a link that might be useful: * link

Also, I would not prune anything during dryness, as that will stimulate the plant to put out new growth. Without ample water to sustain this, the new growth will further stress the plant.