A live CD/USB or https://www.libreoffice.org/download/portable-versions/ .
Do realise, though, that, as far as I know, unlike pictures, Videos are linked to rather than embedded, so put the video on the slide using the computer used for the presentation (or you can try putting the video that is linked to in the corresponding directory linked to by the file - and if you're making your silde with Trisquel and the computer in the presentation room runs Windows it's impossible to do it that way).
