We have left DD with grandparents 3 times while we travelled (she also does overnights about once a month). First for a 3 day weekend at 7 months, for 5 days at 12months, then again for 9 days (we went to Chile) at 15 months. We are planning to leave her for a trip late this summer as well. With the exception of the first trip, we leave her with my parents. They don't see her all that often..maybe every other month. But she does great with them and they really enjoy the time with her. We were supposed to go on a trip next week and DD was going to stay with them for 6 days but I ended up moving jobs and start next week, so I am not going. My mom sure is bummed.
Oh, and I still BF. I introduced milk at 13m and she was perfectly fine with that during our Chile trip but my travelling has not hurt our BF relationship at all.