I have found the 5050 led chips run the coolest of any size and is all that I buy. At 100 degrees, heat is not the problem with my bathroom night light strip. My awning strip is fasten to the alum channel of my Girrard awning and I went ahead and replaced it yesterday... will try and keep better track of how many hours before I have to replace again.
It is only the strips that I'm have problems with, my other $1 leds from China have help up well.
As a side note, I bought 24' of expensive 120V led rope lights for above my kitchen cabinets. It did much the same with 3' sections stopping to work and the rest started to dim. At less than a year (3000 hours) I replaced it with the old fashion incandescent rope light... like the one around my front door which still works after six years of use.