"We will get married after we have moved house."
The 了 in 搬家了 is Change of Situation 了. That sentence would refer to a new, currently relevant situation. This would be something that just happened. In other words, we've just moved into a new house. The 了 of 搬了家 is Verb 了, indicating that the speaker is (or imagines herself) to have completed a task. In this instance, she is imagining the completion of a future act (moving into the house) after which she will likely get married. (BTW, sentences like this are why we cannot accurately equate Verb 了 with the past tense.)
Good answer, keyongming. 送給你一个 lingot! :-) I was thinking about this after I posted what I did above. It's been a few years since I've studied my Chinese grammar, so while I suspected something like this was the case, I wasn't sure. But I believe you're correct.
P.S. This is why we used to call 了 an 'aspect particle' rather than purely a [past] tense marker.