To me, に marks an abstract location/target/object in space, time, etc. "go to tTokyo", "to/for Tarou, there is no home". With that thought in mind, a sentence such as 高橋さんにできる事はなんだと思いますか makes sense to my mind as well: something that can be done by Takahashi; or "to Takahashi, something that he can do". Also, 太郎には…ありません emphasizes that Tarou is affected by this, compared to 太郎は…ありません (and it sounds much better as well).