Code is for humans to read and machines to execute. So as far as it is readable, I won't change long variable names. I've used long names many times, when it is deserved. Most of the times it is longer function/method names, or constants or configuration variables.

However, if a method/function is too long (i.e. too many lines in that single method/function) then it is very likely to have longer variable names within the scope and that method itself is likely to be a good candidate for refactoring. Sometimes the same applies to configuration variables (for example- stuff you read from a json config)