DOTMAP - a sketch
I'll not use graphics editor (sorry!!!), just give a brief description of sites. I'll use previous colors where appropriate.
---------------- First expansion wave (-> close sites) ---------------
Red - 1NW of Clams. Lots of production from hills, fueled by food from Clams and Deer. Production powerhouse, possible military construction center.
Orange - 1N or NW of Clams - with adequate number of both hills and grassland and abundant food - and some coast - a great balanced city, providing money or production as necessary. No specialization.
Purple - 1SE of Crabs - lots of food and grassland - Academy/research center. A few hills to give production when needed.
Gems - tip of peninsula SE of Hogwarts - with Gems, lots of coast and plains - and hopefully a seafood - it should be nice commercial-oriented city. Backfill possible - and i think desirable.
---------------- Second expansion wave (-> not so close sites) ---------------
SouthPower - 1S (possibly SE) of southern Pigs - another production powerhouse (all those hills), fueled by Cows and Pigs. Which may be nice to have. I'd prefer to leave Gems for dedicated commercial city, whether they end up in BFC or nott (see Gems

)
SouthCommerce - 1W of rice - another commercial site; far below Purple of course, but still nice, and possibly a shield for Purple. Gets Wine.
Pink - 3N10W of Hogwarts - general purpose - strong border city, protecting the core.
------ Reconaissance needed (no hard data, but I'd consider them for 2nd wave) --------
NRed - screen site for Red, and relatively close. No details available.
SouthBlocker - 1SE of Dyes - blocks the pass, gets Dyes. I see no food nearby though - so exact location is to be determined. Should allow SouthCommerce as backfill, but would be struggling without food source. May be strategically important.
SW of Purple - land there seems lush, and such location would screen Purple. Highly desirable, but no hard data available.
Incense - closer than further-flung southern locations. May be contested by Alhazard. Land seems nice.
------ Actual expansion proposal --------
General disclaimer: I know You want quite far-flung gambit, but I urge You to start building Dogs once 2 new cities are founded (if not immediately, then at least soon). A token protection seems prudent, and may help some with scouting/dotmap too.
Also, observe costs carefully - and do start cottaging soon. Better to halt/slow expansion for awhile than cripple research too much.
1) Red. As per Your demand production powerhouse first.
Alternate 1) Orange. General purpose means similar early production to Red (so same help for initial expansion), and this location will be more desirable as Holy city (I'm an optimist, ok?

). Also, it may help grow that Floodplains cottage

. Work boat would probably be self-built anyway, due to Hogwarts being occupied with priority tasks.
3) Purple. With 2 production-capable sites settled it seems like high time for research boost.
Alternate: this may be #2, too, if AH is researched quickly and Cows are promptly improved - it may build early Workers/Settlers well enough. In such case, definitely Red as #1.
4) SouthPower. Boosting production and allowing Gems to be backfill.
--------------------------------
At this point empire would have 1 excellent commercial site and 2 very strong production sites, one very good flexible site, and excellent (and also flexible) capital. And a good commercial backfill site (Gems). Excellent base for further expansion, I'd say.
This would be time to recap new map knowledge, look at costs, and decide where/how to go further. General ideas I described above.