Yes, I'm afraid you are being a bit miserable.
Are you and your DH religious or just "traditional"? Is your Dd and her fiance religious? If not, then I'm surprised you would be expecting them to marry in a church.
Many couples marry in "wedding venues" as it is convenient to be able to have everything in one place - ceremony, wedding breakfast, party.
And many venues offer rooms that are convenient for wedding guests to stay over in - guests who have travelled a long distance, guests who want to have a drink.
An evening meal the night before and a group breakfast the following morning are increasingly done out of convenience, to extend the celebrations, for the group to get to know one another, exchange stories and memories of the couple and the day.
You say you don't exactly know the fiancé's family but seem reluctant to take this as an opportunity to build a relationship.
If money is tight, that is one thing (though "traditionally" the bride's family would be footing the whole bill so 2 nights accommodation is comparatively small sum). What are your concerns about spending 2 nights with your daughter and future son-in-law's friends and family?