I recently genned a world that would meet your criteria.
Dwarves were literally extinct after 50 years. In just a few I will edit this post with seed and worldgen info from legends mode, and a map picture suggesting where to embark for optimal fun.
You might need to ignore certain rejections though. Warning: the world is abnormally savage.
I can confirm the 2 initial migrants thing as being what happens with .34.02. (when the world was genned) That's what I have going right now. Plans are to rebuild dwarven civilization from the ashes, build a massive megastructure, and breed dwarves like crazy, then switch to adv mode with dfhack to keep the fortress intact. I should then be anle to retire the adventurer, and start a new fortress in that world with a thriving mountainhome to trade with.
Ok, Here's the the worldgen parameters:
Created in DF v0.34.02.
[WORLD_GEN]
[TITLE:SMALL REGION]
[CUSTOM_NAME:The World of !!SCIENCE!!]
[SEED:DdkfzZ9Scjk6XyYdwDO7]
[HISTORY_SEED:h7B5mgcdh2jYM63YyEjH]
[NAME_SEED:F6nmsTuBVOG2pLAxYE6W]
[CREATURE_SEED:nheJOLVMSG4Qypna13WB]
[DIM:65:65]
[EMBARK_POINTS:1274]
[END_YEAR:1050]
[BEAST_END_YEAR:100:80]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:0]
[ELEVATION:1:400:202:202]
[RAINFALL:0:100:101:101]
[TEMPERATURE:25:75:101:101]
[DRAINAGE:0:100:101:101]
[VOLCANISM:10:100:101:101]
[SAVAGERY:10:100:101:101]
[ELEVATION_FREQUENCY:1:1:1:1:1:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[MINERAL_SCARCITY:750]
[MEGABEAST_CAP:500]
[SEMIMEGABEAST_CAP:500]
[TITAN_NUMBER:100]
[TITAN_ATTACK_TRIGGER:80:0:100000]
[DEMON_NUMBER:22]
[NIGHT_TROLL_NUMBER:11]
[BOGEYMAN_NUMBER:11]
[VAMPIRE_NUMBER:500]
[WEREBEAST_NUMBER:500]
[SECRET_NUMBER:500]
[REGIONAL_INTERACTION_NUMBER:22]
[DISTURBANCE_INTERACTION_NUMBER:22]
[EVIL_CLOUD_NUMBER:11]
[EVIL_RAIN_NUMBER:11]
[GOOD_SQ_COUNTS:6:63:127]
[EVIL_SQ_COUNTS:6:63:127]
[PEAK_NUMBER_MIN:3]
[PARTIAL_OCEAN_EDGE_MIN:1]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:100]
[REGION_COUNTS:SWAMP:66:0:0]
[REGION_COUNTS:DESERT:66:0:0]
[REGION_COUNTS:FOREST:264:0:0]
[REGION_COUNTS:MOUNTAINS:528:0:0]
[REGION_COUNTS:OCEAN:528:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:528:0:0]
[REGION_COUNTS:HILLS:528:0:0]
[EROSION_CYCLE_COUNT:1000]
[RIVER_MINS:25:25]
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:2750]
[CAVERN_LAYER_COUNT:1]
[CAVERN_LAYER_OPENNESS_MIN:0]
[CAVERN_LAYER_OPENNESS_MAX:100]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:0]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:100]
[CAVERN_LAYER_WATER_MIN:0]
[CAVERN_LAYER_WATER_MAX:100]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:15]
[LEVELS_ABOVE_LAYER_1:5]
[LEVELS_ABOVE_LAYER_2:1]
[LEVELS_ABOVE_LAYER_3:1]
[LEVELS_ABOVE_LAYER_4:1]
[LEVELS_ABOVE_LAYER_5:2]
[LEVELS_AT_BOTTOM:1]
[CAVE_MIN_SIZE:5]
[CAVE_MAX_SIZE:25]
[MOUNTAIN_CAVE_MIN:6]
[NON_MOUNTAIN_CAVE_MIN:12]
[ALL_CAVES_VISIBLE:0]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:10]
[TOTAL_CIV_POPULATION:15000]
[SITE_CAP:264]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:528:1056:528]
[RAIN_RANGES:264:528:264]
[DRAINAGE_RANGES:264:528:264]
[SAVAGERY_RANGES:264:528:264]
[VOLCANISM_RANGES:264:528:264]
and here is a map showing civs at year 60, to give you an idea of where to embark:
This will put you on the overlapping territories of goblins, humans, elves, and kobolds.
The most scorpion is the goblin civ. It has 3 demons in charge according to legends. Your gen may vary.