Questions about Stille Nacht

A local store got in some Stille Nacht and I picked up four bottles - one for now, one for 5 years, one for 10 years, and one for 21 years as my daughter is pregnant and I thought it would be cool to share that with my grandson or granddaughter when they turn 21, and from things I read here, this beer could age that long and be good/better. My questions are, this beer already has the most sediment I have ever seen, is that normal? And some of you here have aged this beer that long or longer. Did you do anything "special" like say waxing the bottles (although from the string I read here there seems to be disagreement if that does anything) and do you think it can last that long in a basement cellar (great now at 54 but up to 72 at max in the summer) or only in a constant temp fridge?
Thanks for the knowledge shared!