(Or, you could just take the wife & kids with you...)
The main reason I switched from AT&T to Verizon was because of the better reception in remote areas, especially southern Sierra. With my old, beat-up Motorola Razor I've been able to: make calls lying in my sleeping bag in the hiker's camp at the Portal; make calls from UBSL and Iceberg (though you need to walk up to the ridge for line-of-sight); call from the summit, though I find the best spot is the summit edge south of the hut and not right on top. I haven't made calls, but I do get bars above Iceberg to the notch.
You can also make calls (if you feel the need) from just about anywhere on the East Buttress or Face, too.
I've been up several times with people using Sprint, T-Mobile and AT&T and they almost always need to use my phone. (Their phones will show bars fluctuating, but very rarely do they actually connect.)
And no, I don't work for, nor do I much care for, Verizon. I just know that I can get calls through in some pretty remote places if I have to. I hope that helps.
