"John" wrote in message
...

I'm wondering if there's any way to estimate the remaining life of the
shingles, and whether it's expensive to get shinglers to remove/
replace mounted solar panels if they have to work around them.

Call a few roofers and get them to take a look and give you a free estimate.
If two of them tell you your roof has five years left and the third tells
you it needs to be replaced yesterday, you know who to believe.