I have not seen anywhere, that you need to celebrate an esbat at a certain time of day.
You should be able to get up early in the morning and see the full moon.
If you get up early enough, it will still be dark outside.
The only thing you *NEED* to have, is you.
I have just sat quietly somewhere with my thoughts, while looking up at the full moon.
Just doing *something* is special in itself, and should not be discounted.