Easy peasy. I’ve done it many times. My 3 tier Butterfly wedding cake travelled 3 hours by car to Bathurst fully assembled with no issues whatsoever. I only central dowel 4 tiers and above as ganache makes for an incredibly strong support used in conjunction with boards and bubble tea straws between tiers. If you have to use buttercream though I would central dowel 3 tiers and up……ganache rocks! Haha! :)
Go for it! :)
Raewyn, Sydney, Australia https://www.facebook.com/cakesbyraewyn