If you decide to tow it home (which I have done uneventfully on numerous 4-8 hour trips) here is an idea.
You say you will replace the axle anyway. If time situation and funds permit, go ahead and bring it with you. If you get in a jam, you or a garage can install the new axle and you are on your way.
You will be money ahead of the game instead of having to fix an axle you don’t want. Since you will be changing the axle anyway.
Does the seller have any info on bearing condition?