Currently G series VMs are only supported by US East 2 and US West Azure regions - both of which are not DR pairs. How can Disaster Recovery for G series VMs in the US, be handled?
I have been hoping somebody would write a reply to this! Because it is an interesting question. However, since they haven't I'll put a tuppence worth in (alas, it may be over priced)
It surprises me that they've not put G series into DR Pair regions though.
Firstly, a DR Pair would only protect you from a bad Azure update occurring - which does happen - It wouldn't protect you from local failures i.e. the machine your instance is running on keeling over. Or 'other' datacentre wide failures i.e. Amazon deciding to nuke one from orbit.
So that basically leaves you looking at what you did before DR Pairs were a thing, and possibly what you did before G Series VMs were a thing.
If your VM suffers a local failure, we'll presume you have something in place to create a new one in the same region and carry on as before.
So from a DR perspective your main concern is the East 2/West region going offline. Obviously simply firing another VM in the remaining site isn't a good idea. Unless your application can only use G Series, in which case there's your answer.
If you have Geo-Redundant storage you could replicate your storage to US Central / East and use them as your backup sites with less performant VMs, albeit with reduced performance. This gives you the ancillary benefits of pairing, since you know those sites are protected by this policy.
Working on the presumption that at some point in the near future Azure will enable those sizes in the DR paired regions, I would put work into developing a DR Strategy into those regions so it can be used when they come online, and until then go with smaller servers if the need arises. A slower service is usually preferable to no service.
Since this size machine is only available in two regions, your only options are to failover to a single region and hope! Or to make it work in another region with more servers.