You have a choice here, and what you choose depends upon scalability and the pain in the backside factor!!
Either configure a dialer interface on the HQ router for each, as you suggested, which can be a pain when the amount of remote routers expands as you have to manually create a dilaer for each...
or
On the HQ router configure a Virtual-Template. This will, as the remote routers dial in, recognise that there is no dialer profile to be assigned and create a Virtual-Access interface for the duration of the call. You can use MLP if required i.e.
virtual-profile virtual-template 1
interface Virtual-Template1
ip unnumbered [interface]
encap ppp
ppp authentication [pap | chap ]
ppp multilink
HTH
Ali
