What ability do we have for teleportation?
Theoretically. Well, pretty much anything can be a theory. We know next to nothing about dark matter/dark energy... relativity theory gives us a working model of how space/time functions but what we know about it is precisely why we know the limits in ability to cross the distances required.
I think a lot of people think of 'relative' time as 'changing time'... it doesn't. It merely changes your perception of time. The same amount of 'time' passes whether you are personally experiencing a fast clock or a slow clock.. relative to whom you are comparing time with.