Welcome CW,
I read your post from the other thread as well so welcome to the site.
IMO, since you want to taper your drinking down try to be as honest with yourself as possible. When I say that, lay out your weekend before it starts i.e. activities, dinner, lunch, site seeing etc.
Look at the times where there will more than likely be some type of imbibing involved. Don't follow anyone's lead, stick to your plan. If your husband or the rest of the inlaw's are having 4 drinks in an hour , have 2. If they drink a bloody mary in the morning for brunch having a mimosa (champagne = a little less alcohol content than the vodka)
Also in between those drinks, drink plenty of water so you're full just like you mentioned. I think that's key as well as putting a realistic number of drinks per day that you will consume.
In addition just keep in mind that you want to keep the peace at home and showing that you can control your intake can be a nice motivating factor. I know for me that's been a big factor in being sober for these past few weeks, when things are good at home you can't deny the fact that we're much happier people :)
Good Luck! Enjoy yourself and remember to stick to your plan.