I am curious about this. I saw this article:
where it is talking about how now the second of the two early Solar System probes named Voyager, here Voyager 2, is now on its way to leaving the heliosphere, just as its predecessor, Voyager 1, did some time ago, and thus crossing into the interstellar medium.
It also mentions, however, that this milestone, while it can be considered an important boundary within the Solar System, is not necessarily the "truest" edge, because there are many other bodies, such as the comets of the Oort cloud, that are much further out than this point and yet still gravitationally bound to the Sun and thus could reasonably be considered as part of the system. Moreover, it mentions that the last of these bodies will only be passed in around 20,000 years, or about 600 gigaseconds, from now - though other sources suggest there is considerable uncertainty as to where exactly these bodies end, especially with regard to the Oort cloud itself.
This, then, naturally leads one to wonder as to what will have happened to the craft in terms of their physical condition if and when they finally do reach the "actual" boundary, however you want to consider it, such an extremely long time in the future. Given the uncertainties in just where the "true" edge lies I will just say for these purposes imagine we are looking at the Voyagers after 1000 Gs of space exposure (about 31,700 years).
In particular, while space is sometimes considered as a kind of "ultimate preservative", perhaps because of the vacuum's ability to mummify dead human flesh and so prevent it from dissolving by bacterial and enzymatic digestion, it actually contains many degradative hazards of its own, such as micrometeorite and dust impacts and the ever-present barrage of cosmic radiation, that in fact can actually ruin things that would not otherwise be ruined on Earth - e.g. consider how that it is predicted that (if it hasn't already happened) Elon Musk's Tesla Roadster will be bleached white by the solar UV flux and the plastics degraded into rubbish making it rather less attractive as a museum piece for any future space explorers.
So my question is, given this, if some hypothetical future exoarchaeologist were to set out at around the indicated time in a much faster craft to catch the fleeing probes, would they still find anything? Would the probes even be physically cohesive at all or would things like micrometeorites and dust have disintegrated their structure? If still cohesive, how badly damaged would they be? Would any of the electronics - even being generous and saying just individual components only and not the whole circuits - still be functional if a power source were available, after exposure to millennia of very high energy ionizing radiation?
