I doubt you could sell your collection online.  Wine enthusiasts would want to look at the colour and condition before buying or if they buy online it would be from reputable sellers.  Since you have been keeping them for years why not just move them with you so that you could continue to indulge in this hobby in your new location?  Freight may be a bit more expensive but you may not be able to replace your collection at the same cost not to mention some vintages may be irreplaceable.

If your collection is too huge to be moved then try selling them to friends in your wine circle or drink up