Getting to Magome for hike

We are having trouble figuring out the logistics of getting from Tokyo to Magome on Monday May 5 (end day of Golden Weekn) to do the walk to Tsumago (where we'll stay overnight). Short of leaving Tokyo at 6 am, we will miss the luggage forwarding service at 11:30 am. One option to save a bit of time, is to take a cab from Nakatsugawa station to Magome instead of the bus, but I can't figure out the cost. Another option with more flexibility is to take the bus to Magome but use a taxi to send our luggage to Tsumago instead of the regular luggage forwarding service, but again, I can't figure out the cost and how to set it up. A third option is to use the Takuhaibin luggagge service from Tokyo, but I'm concerned about how early the day before we'd have to part with our luggage and we'd still have to hike with our overnight stuff like toiletries, change of clothes, etc. I've also considered going to Tsumago first to drop off our luggage, but that really takes up a lot of time. Any suggestions? I've spent way too much time trying to work this out, to no avail so far. Thanks much.

Why not go to Tsumago first, leave your luggage at the place you're staying, and then walk to Magome? You could then catch a bus back to Tsumago. Even if you can't check in, you can usually leave your luggage as long as someone is there to take it.
http://www.japan-guide.com/bus/kiso.html
If you missed the last Magome-Tsumago bus, you could catch one down to Nakatsugawa and get a local train back to Nagiso and at worst take a taxi to Tsumago from there.

Unfortunately we can't go to Tsumago first because train connections mean a much longer trip to get to Tsumago, and we really want to walk from Magome to Tsumago. But thanks for the suggestion.

The taxi fare was calculated to be about 4,000 yen according to the Web service from Nakatsugawa to Magome. However, if the road is crowded, it will go up.
https://maps.google.co.jp/maps?hl=ja&q=http://www.taxisite.com/kml/far...
If you plan to use the porter service from Magome to Tsumago, you have to apply it in Magome to 11:30. Do you plan to ride the bullet train to Nagoya?
If so, it would be possible to arrive at Magome to 11:30.
Use fee of Porter service is 500 yen per one.
http://www.japan-guide.com/e/e6078.html