Weather? Who the heck knows. Last year at that time it was snowing up high and raining below. I got rained out of a trip to Moose Lake that weekend (12th). Start keeping an eye on the patterns developing now. When I looked up the drainage last night, it was snowy but there was a lot of rock showing. It's snowing in B-town and the surroundings today, so I would guess pretty different now.
I think it's 5 miles from the TH to Meysan Lake, which is the end of the trail at the base of the cirque heading up to LeConte, Mallory, and Irvine to the south and west, and Lone Pine Peak to the east. Amazing place, really. There is good camping at Grass Lake, which I think is about a mile below Meysan. Should be well-sheltered from any wind, still at tree line, good water source, etc.
It's a steep climb, a bit steeper than the MT if you ask me, but it's well switchered-out. In fact, on the way out, the switchers seem to run on forever... But if you just take it slow with the packs I don't see why the boys couldn't make it. Trail is well-developed and marked, but if there is still snow, there can be some tricky crossings on the gulleys.