I think we will get an expansion in either June or July; at this point, I'd put it at 50-50 odds which month it is. Which means it could potentially be in either the spring or summer roadmap.
However, I also think that either way we will get an announcement about the expansion during the spring road map.
Why? Well, we had an unusually long lead time between the announcement and the release of Cottage Living last year. I believe the longest ever in TS4. At the time, we speculated that it was announced so early for one or both of the following reasons: (1) lots of people were underwhelmed by DHD and they knew there would be a lot of (well deserved) hype for Cottage Living. (2) The EP was being released much later than the usual June EP release.
In this case, if it's a June release, it will be both announced and released in the spring roadmap. If it's in July, then much like Cottage Living, it will probably be announced earlier, both because of the later release and because of all the MWS drama.