There is camping at both trailheads, and at several places on the way between Ovando and Missoula. The later provide access to the Blackfoot which should be fairly ice free, and has many hard to catch trout.
I could easily pick folks up in Missoula Friday evening. We could get some beers and good food and go camp somewhere.
As for the fitness question: mileage will be reasonable, and the hiking and trail breaking could be quite easy or pretty hard. We'll have people to share the load, but in the worst case scenario of slushy snow that doesn't help a huge amount. In short, if you regularly do 15 miles miles a day on summer backpacks in the mountains this should be quite doable, though it might feel hard if conditions are difficult. Days will be longish by late March, so plenty of time to get it done.