Carradice: What I wonder is, these integrated graphics are enough to play modern strategy games reasonably well, as well as third person RPGs
The only modern things they can be used to play reasonably well @1080p are competitive shooters and maybe MOBAs. You have to go further back in time with everything else, or drop to 720p. I found that almost everything released in 2009 and before that performs admirably @1080p. I'm currently playing DA: Origins for example, all maxed out @1080p and it handles it no problem.
In terms of strategy games, just to count some I have tried and can confirm work well: Supreme Commander 1 & 2, SpellForce 2, Majesty 2, Anno 1701, Anno 1404 (though not maxed out), Sins of a Solar Empire - Rebellion.
I have yet to try Iron Harvest or things like FrostPunk, but I expect they'll be a bit too much for it to handle, to be honest.
Also, according to some gameplay footage I've seen, it's possible to play The Witcher 3 and Red Dead Redemption 2 on it at Low 720p, but I'm not sure if that's really worth it.