On restringing a stringed instrument. If what Dr. Bill says is true (as I'm sure it is) about the structure of a cello, I would worry more about warping or even cracking the instrument than degrading the tone. If a piano is left untuned for a very long period, you can't get it back into tune at one retuning because you will put too much tension on structures which have adapted themselves to new conditions and aren't flexible enough to take the pressure of the strings at the correct tension. It has to be done in small increments over months and it may be impossible to ever get it back in tune. My mother was greatly put out when I declined to take her piano when she moved into a retirement community; it hadn't been tuned for 20 years and would have been a white elephant to me.