Yankel berel, your conclusion is that there is a “measure of life in Yaacov’s body”.
Yosef and his brothers would not bury their father if his guf would still be physically alive. As it says in the posuk that he “expired”, Rashi himself says the posuk says “expired but not died” . What does it mean that Yaacov expired? Yaacov is alive but his body expired. A little further in the parsha it says that the brothers of Yosef saw that their father DIED with the loshen “mes”.
Rashi does not contradict any posuk in the Chumash and therefore he did not write that Yaacov’s guf is physically alive.
In conclusion, Yaacov’s guf is not alive in a physical sense. But his guf is alive spiritually by Yaacov’s soul being dormant in his guf. In that sense it would be “a measure of life in Yaacov’s body”.