Every school holidays when we were kids, we used to watch the same
movie at my grand parents place, but we can't remember the name.
It is an old time movie (in color). The only thing we remember is a
song that went 'where are you my pretty Pauline.... The basic plot was
a older guy who fell in love with a younger women. So they could be
together he was frozen & he was to be unfrozen later on, when she was
older. At one point his frozen body was floating around a lake or
maybe it was Venice.

Not much to go on, but any assistance would be great.

Dear c00lridge,

The movie you have in mind is, without any doubt, the 1967 film "The
Perils of Pauline". I have two reasons to believe this. First, because
of this excerpt from a plot summary [1]:

"Austin [who plays Pauline] comes to the Big Apple, falls down a
sewer, and is saved by 99 1/2-year-old Horton, the second richest man
in the world, who would like her to marry his one-year-old grandson.
In order to effect that union, he tosses Austin into a deep freeze to
wait for the infant to grow. Boone [playing George] has himself frozen
as well, despondent over not being able to locate Austin.(...) The two
marry and go off to Venice where their gondola begins to sink as the
film ends."

Second, because the song you remember, "Where are you, my pretty
Pauline", was sung by Pat Boone in that movie.

Unfortunately, "The Perils of Pauline" seems currently not to be
available as DVD or VHS yet. Please also note that this movie should
not be confused with three other films of the same name which were
made earlier.

I hope that this answers your question!
Regards,
Scriptor


Sources:

[1] TV Guide Online: Movie Database - The Perils of Pauline [Google Cache version]
http://66.102.9.104/search?q=cache:aWOmI4sceuIJ:www.tvguide.com/Movies/database/ShowMovie.asp%3FMI%3D10483+%22Perils+of+Pauline%22+freeze&hl=de%20target=nw

The Science Fiction, Horror and Fantasy Film Review: The Perils of Pauline
http://www.moria.co.nz/fantasy/perilspauline67.htm

Internet Movie Database: The Perils of Pauline
http://www.imdb.com/title/tt0062117/

Internet Movie Database: Pat Boone
http://www.imdb.com/name/nm0004769/

Search terms used:
"my pretty pauline"
://www.google.de/search?hl=de&q=%22my+pretty+pauline%22&btnG=Google-Suche&meta=
"Perils of Pauline"
://www.google.de/search?hl=de&q=%22Perils+of+Pauline%22&btnG=Google-Suche&meta=
"Perils of Pauline" freeze
://www.google.de/search?q=%22Perils+of+Pauline%22+freeze&num=20&hl=de&lr=&newwindow=1&c2coff=1&safe=off&start=0&sa=N
"Perils of Pauline" freeze venice
://www.google.de/search?q=%22Perils+of+Pauline%22+freeze+venice&num=20&hl=de&lr=&newwindow=1&c2coff=1&safe=off&start=40&sa=N

Exactly what I was after