I'm going to chime in with a little different opinion. You really need to look at your babe's personality, relationship with the grandparents, and attachment to you and figure out (the best you can) how he'll handle the time away. I've had several trips away from DD1 and I know hard hard making the decision can be. Here's my experience:
Went away for a work conference at 12 mo. for 2 full days (one overnight). She was still nursing a lot and she did great with her grandma and dad. No issues at all with nursing or any apparant separation problems when I returned.
DH and I went on a weekend trip (Fri-Sun) when she was 18 mo. She also did great with my mom and dad (who she's really close with). At this point she was still nursing but had stopped taking bottles of BM while I was at work 2 days/wk. I sent bottles with her but she didn't drink them at all and didn't even want the BM out of a cup. Again, so problems with nursing or attachment when we returned.
I went on another work trip when she was 20 mo. old this time for 5 days. She was with her grandma and dad and I think she had a blast. DH did so much fun stuff with her and it really gave them a chance to bond. She was still nursing and there were no issues with it when I returned.
When I was gone for the trips for work I think she did so well because she was with DH. I would have probably had a really hard time leaving her for 5 days if DH wasn't with her. As it was I cried each time I left! If I were you I have no problem going away overnight, but I would wait a bit to plan the next trip and just see how you feel when the time gets a little closer.
If in the hands of loving caregivers who your DS is attached too (like grandparents) I think it can be a great experience to bond with them. Generally they are totally devoted to caring for the kids and do all kinds of fun stuff.
From my experience and from what I've heard it's rare to wean after such a short time. You, however will probably be really uncomfortable and will definitely need to pump.
I hope this helps, and good luck making a decision!