I would be very cautious about August collection, particularly for beginners. Honeysuckle will most likely live regardless, but hophornbeam and hackberry in your area will be challenged not only from initial collection, but overwintering in Minnesota. What is likely to happen with both species is once collected, they begin growing new roots and top growth, only to be frozen before either of those harden off to handle winter conditions. If you're only digging seedlings and can get all their roots and no top reduction, then things might work out (but what's the point of collecting seedlings--collection is about getting older, weathered trunks...) Overwintering in heated place will only make things worse, as new growth will continue, but won't be able to sustain itself out of season in a darker or completely dark location indoors.
Why not wait until spring? Are the trees endangered by development, etc.?
Patience and respect for the living things you're digging up and taking responsibility for are important parts of bonsai...