Steve, the Dragonfly is a nice stove, particularly if the trips with your boys will involved cooking pancakes, bacon and eggs, etc. However, I wouldn't be concerned about the ability to burn multiple fuels. Once in nearly 15 years did I ever find the need to burn something other than white gas in a liquid fuel stove (perfect storm of bad stove maintenance).
If you compare the actual stove system weights, MSR's white gas Simmerlite is equivalent to a hair lighter than their remote-canister version, the Windpro. How so? Stove canister weight is less for the spun aluminum cylinder vs. the steel cans used for the iso/pro. Could you make a canister work in winter? Well, yeah. But I've found that liquid fuel stoves are a lot less fuss when the mercury drops.
If you're talking the "much more light weight" upright canister stoves, you can pretty much write them off for winter use. Yes, there are tricks to making them work. But I don't want to have to mess with reliability, having the canisters on my person and in my sleeping bag, pots of water, or other such fun.
Check out the Simmerlite. Comparable weight, no fuss. Great for "real" winter (0*F, give or take whatever temps you might reach).