All I was able to find was a question related to moving the bottles, but not the demijohns during secondary fermentation.
I really want to brew some elderflower wine and starting after I move is not an option as the flowers will be gone by then. How likely is the agitation related to moving the demijohns to mess up my fermentation process?
Two things. You can delay the wine but picking and freezing the flowers. Should not effect the flavor or quality.
Second thing, a demijohn, carboy or whatever is like a giant bottle so in effect if you have all your chemistry (sulfites and such) at the right levels and you can move the demijohn with care, it should change nothing. The caveat to that is if it's a really long trip and major temperature swings, then I wouldn't do it. But if it's across town, go for it.
It will be fine. Just keep it covered from light and cool. Make sure your air-lock doesn't lose it's fluid in the move. Only concern is if your changing elevation from high to low by 2-3k feet, you may suck in fluid from the air-lock. If this is the case just cover the fermentor with sanatized foil, use a lot and try to go down the sides 3-5 inches from the opening.
Agitation is fine for fermentation. If anything it will help keep the yeast in suspension more.
