Hyper V over VPN?
Solution 1:
Obviously, your choice is a Hyper-Converged scenario (Hypervisor and SAN are on the same hosts). From my experience, without improving the network you won't get the High Availability. But you can ask HP or StarWind engineers if is it possible. Hope it helps.
Solution 2:
While this may be technically possible, it's a bad, bad idea. Storage systems require consistent, low-latency connections. That is not going to be possible over a VPN connection. If you want HA, you'll likely need to investigate volume replication between sites with VM failover.