Yes you can freeze kielbasa and sauerkraut and it will be just fine.
Once you're ready to freeze it just put the kielbasa and sauerkraut into a freezer safe container or a Ziploc bag and then place it in the freezer like normal.
The kielbasa and sauerkraut will keep in the freezer for 6 months to a year but if you want the freshest taste from it you should eat it within a month or two of freezing.
Still the kielbasa and sauerkraut when frozen will remain very safe to eat well past a year although it just loses it's freshness.
I make extra kielbasa and sauerkraut and freeze it for later to use so I always have some ready to go.