Azure Subscriptions

I've got an MSDN account that is connected to my corporate Office 365 and it has Azure subscriptions that come with it. ( Developer subscription and Visual Studio Subscription) Both of these are free.

I've now create a new demo tenant at demos.microsoft.com. As a MS partner these also come for free. Ok, I'll have to create a new tenant every 3 months but that is ok.

I now want to do some developemnt work in my demo tenant and I would like to create an Azure AD App. As part of this all I will need to create a storage account and therefore I need to have a subscription created. 

Is it possible to move one of my MSDN releated subscriptions to this demo tenant ( and the once I'm going to create in future)?

I tried using the free 30 day trial within my Azure connected to my 90 day demo tenant but that doesn't let me do this.

Am I missing any easy option?