Anyone know if you get get there? I'm using a routing map that says that I can't.

There is no trail. You'd have to leave the BWCA, head down the Echo Trail a bit.

I've followed the creek to between South Hegman to Nels in Winter. There might be a little used legacy trail along the north side of the creek. Haven't tried carrying a canoe over it.

Satellite images makes it look more difficult than the other maps I've looked at.

It's less than a half of a mile, I'm sure you could make it one way or another.

There is a concrete boat ramp on Nels and a small parking lot.

What are your intentions? Sounds like you're trying to do a loop from Mudro to South Hegman. I'd say go for the bushwack. You could always leave your gear at Hegman and take just the canoe through Nels and Picket to get your car.
Google Maps says it's only 8.2 miles by road. I've found these jogs from EP to EP go by fast after a trip... Somewhat of a bittersweet way to end a trip, however. Next time I think I will be unloading my gear, parking the car at the exit point and jogging back to the entry point before setting off. No telling if you'll actually encounter traffic but from my experience hitchhiking is easy up there if you're only a person with no packs. You could always stash a bicycle at Hegman, too. Or another car. Or pay for a front-side shuttle.

Maybe you're just trying to avoid the infamous Trease Portage...

If you're trying to work the Hegman pictos into a larger loop that doesn't include the Trease Portage, or you're trying to access Mudro via Nels from a Hegman permit I believe you would be breaking the rules. Your entry permit becomes void as soon as you leave the wilderness to enter Nels of Picket, but I personally would overlook a short jaunt like you're talking about. Technically, everyone that paddles the border route through Gunflint Lake commits this same crime. Alternatively, if you're trying to turn your Hegman permit into a Mudro permit, obviously you're going against everything the permit quotas were set up for and I would have to strongly discourage. I don't see any reason to do something like this when the permitting system is working so well. /s

Forgive me if I sound accusatory or abrasive, I'm sure you intend on following the rules.

The walk on the road isn't bad, assuming you're doing a loop through Mudro starting at SH and ending at Nels. I did it a couple of years ago. Just left my canoe at Nels and came back w/ the car.