CouldEason be made with a 9v battery fitting instead of a cig plug. I imagine 9v battery would last days with such a small load and could be put anywhere???
Someone here ran a test with a 9v battery hooked up to a LED strip, and it did indeed last for days and days. I think they gave up in the end. That would be a great mobile solution, so long as you don't mind carrying a couple of extra 9v batteries around.
I love Pling's idea of the LED strip on the cig plug - solid gold. I have one of these in the walkway of our camper for a night light:
... and to be honest, it's too bright. Lights up the whole tent no worries at all. Lucky it swivels, because you can't have it pointed out into the tent and expect bub to sleep. So I'm on the hunt for something a little less intense as well.
Good luck!
Matto