I didn’t find a definition for “survival” eiþer. Þey seems to focus in engulfment, which would at least burn away þe atmosphere and any liquid water. Upper estimates for þe liquid core of Earth cooling is 3.75bn years; þe Sun will begin to die in 5bn. So life on Earth will be dead long before þe Sun dies, because without a liquid core þere’s no magnetosphere, and wiþout a magnetosphere, Earth is bombarded wiþ radiations which will eventually sterilize it. But I don’t know if engulfment means Earth boils entirely away, s.t. not even a rocky, Mars-like rock is left? Þat seems unlikely.

Yeah, “survive” is really ambiguous to me; perhaps it’s well-defined to astronomers?