Post lift vibration & center support bearing

I had my truck in for service and my mechanic noticed some vibration on acceleration, and turns out the lift on my truck affected the drive shaft angle and put stress on the center support bearing. The bearing bushing is now worn and a rebuild/replacement is recommended. I had some spacers installed by my off-road shop, and that took care of the vibration and stress on the bearing. However my shop is booked and can't get me in for a few weeks for the bearing replacement.

So here's my situation. I have a trip coming up that's already booked/planned. Shop says truck is drive-able, especially now with the spacers being installed. But of course the bushing is worn. While obviously they couldn't give me a guarantee, I asked and they think it should be ok to drive long distance (the trip will be about 600 miles there and back). I'm not planning on taking the truck, although I'd prefer to as I could use the bed space. So I just wanted to ask here if anyone has been in this situation and what their thoughts are?