From a quick scan through the films and the first series (I may have missed some, but I think this is enough to illustrate my point):
film 1: 2 buckets
film 2: 1 bucket
s1e1: 1 bucket
s1e2: 1 scene with ice but no bucket that I could see. 1 regular ice bucket (you can see that it is only there temporarily, and it is used to hold wine cold, not to store ice cubes for whiskey). This is the first episode with no unexplained buckets.
s1e3: 1 bucket that was there only in the evening, so I suppose this one was in the freezer during the day and only taken out in the evening, we even see this scene later on in the night and the bucket is gone again. 1 more bucket that was used during a party, that makes sense.
s1e4: 3 buckets, although with the second one I do not have 100% confirmation it is an ice bucket.
s1e5: 1 unconfirmed but high confidence. 1 scene with ice but no bucket that I could see.
s1e6: 1 bucket, 1 suspected - locked in a closet with definitely no refrigeration next to glasses.
s1e7: 1 bucket, but with an expected visitor. 1 scene with ice but no bucket that I could see.
Another thing I've noticed is that they often use some big lighters, but not as often, and it does not seem as bizarre to me as these buckets. A large decorative lighter in an era when people regularly smoke inside makes sense. But these buckets are always on some counter top or something, a decorative element - you never see them hidden in a freezer. They just seem strange but cool to me.
Dunno why, but I kinda crave a cigar now, may buy one next week.