If you mean "Wait until I'm really sure that the people who registered the domain name don't want it" then it still isn't a good idea.
It is really amazing that there are people who will not pay their renewal, then let months go by, and wake up one morning *outraged* that they don't have their domain name anymore.
If, in that situation, you had paid the renewal on the assumption that they had no interest in the name, had died, had ceased to care, or whatever, then all you've really done is put yourself back at square one, where at some point along the line you are going to impersonate them in order to change the info.
It's not something you want to get called on, even if the possibility seems unlikely.
No, you can't impersonate dead people either.