tires badly worn

[The Gecko_imp]

Could use your help with a difficult decision. I will help a friend and ride a (other man's) bike some 500miles to his home. Appears that the bike is in good shape, brakes work, in other words she is safe to ride. But - from a distance - seems the tires are worn completely worn, and probably very old. The current owner says they hold the pressure over a few days, but they have little traction. Probably looking like the tires Munro prepared himself (in the movie) before tempting fate.

So ... I feel like doing it, and staying out of (major) rain, gusty winds, puddles and of course bad roads on that trip.
Any thoughts ?