Just go ahead and JB it. I have a tethered JB and have for about 2 months now. I have never been in a situation where my phone has needed to be turned off without me having a computer near by. I'm careful not to let my battery ever die (I bought a car charger) and I never turn off my phone, so I'm never in a situation where I can't turn my phone back on.
I thought it would be a huge inconvenience, but so far it hasn't even been an issue.