Evolution of Homo Erectus to Homo Sapiens
It is not plausible that members of Homo erectus would survive and remain a separate species from Homo sapiens. For members of Homo erectus to survive implies that there wasn't significant interbreeding with Homo sapiens, which would require a significant population of Homo erectus. 

There is some evidence that Homo erectus and other hominids interbred with Homo sapiens. So it is more likely that there may be some people with more genetic traits from Homo erectus than others. However, by significant interbreeding, there currently only exists a single species that may contain ancestors from multiple hominid species.