That campstove that turns fire into USB power is the coolest thing I've seen all day. The MVP is a good idea however for a higher mAH battery you'll probably find that it's not going to keep you going for days most likely. When I first bought my hana I took it to a friend's for an afternoon to vape and charge the battery off my MVP, for a VTC 5 that came at maybe 20% charge and an MVP reading 4.1v while
vaping it took it from ~20% to 80% in a few hours, but that completely drained the MVP to the shutoff point. So extra
batteries or some of the charging solutions here would be a better idea, since an MVP is going to probably charge 1-2 18650s for you depending on usage.