To monitor off network sites (sites which we can't reach)

Hello everyone,

We have a new requirement to monitor our off network sites (sites which we can't reach). So while exploring about the possibilities we came up with the idea of putting an additional poller on cloud to do that. Basically we are thinking of establishing a secure connection between the off network sites and that poller with IPSec tunnel. Our main poller and DB is on premise we just want to put a single poller on cloud for this.
Please let me know the feasibility and if any other options we have.
Thanks