IPv6 multi homing understood or not?

Well, I understand that I"m probably working on something that's not yet fully understood: IPv6 multi homing.

Use two internet connections

As we have two ISP's that both use private addresses for their end users I don't have a public IPv4 address, which was one of the reasons to early adapt IPv6.

World IPv6 Day put my attention back to IPv6 even though it's not my/our main business, so during the last week or so I finalized my IPv6 setup for our home office:

I am using a Gogo6 tunnel to two Gogo6 locations.
Each of those tunnels gives me a /56 network.
I put two addresses to each of my routers, one based on the first /56, one on the second
I advertised the routes to the Gogo6 network.

Two logical IPv6 networks on one physical?

Of course my main question is what is actually happening now and my main interest is still using both connections at the same time to speed up my internet and my secondary interest is to have a fallback to one of the networks in case one connection breaks.

Of course the last I don't have any control over as I don't control how far my networks are 'advertised' into the IPv6 network.

After reading some articles about IPv6 multi homing I realized there is no final solution for that (yet). Or is there?