This slide shows the LM5017 isolated evaluation board, set up with a 48 V input, 3 W output, and 700 kHz switching frequency. These boards are available on the LM5017 product page on ti.com. While these boards are not optimized for solution size, it can be seen that there really is not a lot of PCB area dedicated to actual component usage. The thermal image on the left shows that the device runs relatively cool.