You can go without insulin for an hour and a half. For me, if I could, I would eat just before (taking insulin with it). This would probably make you go a bit high, but high is better than low short-term. The only insulin you'll be missing is your basal.
I went without insulin for about 4 or 5 hours once when I had a persistent low. My thought was, "If I've got too much insulin (and am going low) the last thing I need is my pump.