I had success with a single transfer, well kinda. I ended up miscarrying for unknown reasons. Transferring two only increases risks of multiples according to my RE.
I know it for ethical reasons but you really should consider freezing your embryos or at least fertilizing more than one egg. Also if you just fertilize one egg chances are the egg may not fertilize and/or continue to grow. Then you have no embryos to work with. And your chance are dramatically reduced by limiting fertilization to just one egg. Its best to fertilize all eggs collected OR to do natural IVF where only one egg is collected and fertilized. Fertilizing rate of eggs is about 60-70% so if you collect 10 eggs chances are 3-5 of them wont fertilize or wont fertilize normal. I am sure you and DH have discussed it but you really should consider fertilizing all of the eggs retrieved and/or freezing any remaining, esp if you want more than one child. Good luck!