How can I resize a node without downtime?

I understand that resizing a Linode requires some downtime, you shutdown the server, snapshot it, provision a new instance with all of the characteristics of the previous one except the resources of the new size, and copy the data to it. (or something roughly like that).

I would like to find a way to do roughly the same thing without bringing the site down, or at least avoid it being down during the time consuming data copy part, which would roughly entail:

1) Take a snapshot of the server.
2) Create a new Linode from that snapshot.
3) Resize the snapshot to the node size I want.
4) Transfer all the important details like ipv4 and 6 addresses to the new node
5) Start the new node
6) Decommission the old node.

Maybe there needs to be a 3.5 in there of shutting down the old node, and perhaps we need to prevent changes to the website between steps 1 and 6 or they'll be lost when the new site comes up. I understand that we'd end up paying for a bit more server, because briefly two instances of the node being resized would be running, but I wouldn't mind paying a little bit more if I could avoid taking the site down for 20 minutes. It would be ideal if I could automate this into a script using the Linode API.

Is this possible?
Is there a better way?
…and…
If my approach is the right one, how would step 4 be accomplished?