It has been my experience if a Plant drops brown/dead leaves, It is trying to make a come Back.
If the Brown leaves stay on the plant and are hard to pull off, The plant is done.
Of course this is not written on the wall and only a general observation. Mother Nature has made a lier out of me more than once.
The Tree in the first picture looks like my customer plants in the fact the protected side is still Green. But I am 2,000 miles South of you and in a totally difference climate. So I don't know your area or problems.
You can lead a Donkey to water but you can't make the Jackass Drink
"As Americans you have the right to be stupid." John Kerry
"Life is tough, but it's tougher when you're stupid.” John Wayne.