Rhododendron Impeditum dead

I have a Rhododendron Impeditum which has been in a container for about 5 years (it has been repotted into a larger container in that time).
Last year I moved it from the back garden to the front, next to the front door under the porch. It's not a proper porch, just a bit that sticks out. I have just looked ta the plant aand it is bone dry and looks on it's way out. I hadn't realised how much the porch and the leaf canopy keeps the rain off.
I have given it a watering can full of water, but I would like to know whether if it doesn't perk up it would be worth cutting it back to see if that helps? It is about 1 ft high and 2 ft across.
I will be sorry to lose it as when it flowers it is beautiful, but I guess a dead plant is an opportunity for a new one!

 

Try a scratch test.
Scrape a little of the skin off on a stem with a fingernail and look to see if you can see any sign of green underneath.
If there is - it's still alive.
If not, then that bit is dead and try some other branches and the main stem.

If you see any green anywhere then it indicates the roots are still functioning and it should survive.
If there's no sign of green anywhere, then it's time to replace it.

 

Thanks @Pete8, the leaves are still green but a browny sort of green if you know what I mean. Hopefully I've caught it in time.

 

Let's hope so, but if you're in doubt, try the scratch test.
Also, don't be tempted to feed it anything at all until it's well on the way to recovery, just try to ensure it doesn't dry out.
Fingers X'ed

I have 2 bays in pots by my front door - like you I recently found the compost to be bone dry, so hope I've watered them in time..

 

Thank you @Pete8, and good luck with your bays.