The rehearsal dinner is just supposed to be the wedding party and the very immediate family such as the parents of the bride and groom, grandparents, parents of underage members of the wedding party such as the flower girl, ring bearer, jr. groomsman, or jr. bridesmaid, etc. That is why it is called the rehearsal dinner. It is supposed to be for those participating in the wedding rehearsal. Of course, couples may invite who they wish and make it what sort of affair they wish such as a barbecue, but the couple should not feel obligated to invite the larger guest list to the actual wedding just because they travelled. If a couple feels that it may be awkward to hold the rehearsal dinner in the same hotel that some of the guests may be staying at, then they can have the rehearsal dinner at another restaurant, etc. The rehearsal dinner is meant to be a more intimate occasion right before the wedding which can make it very meaningful for the very immediate family and the wedding party. It is also meant to help everyone relax, not turn into a second wedding reception.
