When hatching wyverns, they will have just enough food to survive until they are fully matured, no matter the server settings. Once a wyvern is tamed, it can be fed with just raw meat, which should be relatively easy to get if you are getting wyvern eggs.
I got a level 150 lightning egg and I was so excited to hatch the egg...that when I went to put the egg down I accidentally ate it instead. :( ps4 users: R2 ISN'T GONNA DROP THE EGG YOU'RE GONNA EAT IT LIKE ANY OTHER EGG. REMEMBER THIS. LOGIC BEFORE EXCITMENT.