It's possible, yes. Grymforge will still be there waiting. (unless you've already mentally contacted Nere through the rock fall, in which case the quest to free him is timed)
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Somewhat related to your question, though. If you do the monastery and creche *before* you rescue Halsin, then Halsin will be defeated by the time you get to the goblin camp. And all the tieflings will be gone from the grove. They also won't show up in act 2.
I know you're not asking about doing the creche before the goblin camp. I just wanted to mention it as an aside because it surprised me.
