Hello; I strongly agree with the danger of having someone feed the fish. Lost a tank of nice fish that way. Non hobbyist will feed too much or too often.
One of the ways i feed newly hatched fry is to boil a gallon of water and throw in some lettuce leaves. Set it aside for a few days. Usually takes a few days for the wrigglers to move around to feed. By the time you get home the jar will be loaded with infusoria. It also will stink. If the tank in in the living space of your home and you are married such could be a problem.
I have not faced the exact situation of being away with newly hatched fry. Fair chance fry will find food which adults ignore. If you happen to use an automatic feeder likely will not be a problem.
Here is something I have not tried so have no idea if it will work. If you doe not have any plant eaters in the tank after you boil some lettuce leaves, throw one in the tank just before you leave. Not a big one. Not enough to sour the tank. I do not know if the adults will eat such and even if they do might still work out. If adults do not eat it will soon have tiny critters on it. If the adults do eat it much will pass thru the gut and the poo will still be a food source. Not ideal and may not work. May be bad in a way I do not anticipate.
likely just do whatever you normally do when being away is the best idea. If this batch of fry do not make it you have a breeding pair and they will try again. First time breeding pairs often enough do not do well the first time anyway.
Good luck.