This one is trickier because there was a number change.
Montpelier Terrace is on the east side of Montpelier directly below the Church. There are 5 houses in a terrace and on the earlier censuses they are numbered 1 - 5 from the bottom up - with one detatched house below them.
This side of the road was renumbered with even numbers and No 1 Montpelier Terrace became No 4, Montpelier (the first house becoming No 2 Montpelier) Therefore, to answer your question No 2 Montpelier Terrace became No 6, Montpelier.
I hope that makes sense - take a look at Google street view which should make it clearer! Happy Christmas!