Not if I get there first!
I am almost in the same boat (except my vacation is further away)
If it isn't broken, and there are so signs of slowdown, I would leave it.
Keep the NIB one for an emergency, and have a slick union plumbing setup so it can be hot swapped.
That being said, if you have time to clean a pump and get it back on the tank, that is always a good thing. I just wouldn't do it <4 days till you leave.
Also, maybe we make a tank sitting network of trustworthy reefers?