The case for above ground dwelling:
It is simply far easier to build a house above ground then to dig below and then worry about groundwater, ventilation, and the fact that at some time you might live beneath a glacier. OTOH, the climate will (according to an Eric fagan book an the last ice age whose title I forgot) be drier, maybe even sunnier (not in your case with the particles etc.). I'd expect realy slow movement away from the glaciated mountains and onto the, due to lower sea levels newly existing, coastal plains. Some might even adopt a semi nomadic lifestyle - cheaply produced houses from compressed earth bricks that are left after a generation or so, only as much property as can be actually moved.
The basic ice age nomad package may well consist of a press for compressed earth bricks and a ventilation/heat exchange system for their temporary (sort-of) passivhaus!
Existing harbour cities will likely remain intact (coasts are glaciated last, if at all, unless you live in Norway) and gain interesting nwe real estate due to lowering sea levels.
Given that the soviet union managed to move whole factories ahead of the Wehrmacht and behind the Urals, I suggest that a sheer production facility can always "outrun" a glacier.
The case for below ground dwelling:
This allows you to stay in one place, which in itself is not worth much when the place is covered by ice. However, you can't move mines anywhere, so I'd find it reasonable when major production facilities stay near the resources they consume. This could mean to move factories into old excavated mines. Minig is hard for reasons stated above, so I really think this will only happen where coal or ores are mined anyway or where the ground is exceptionally soft rock, like carst areas.
Our below ground areas will likely use a combo of geothermal heat, solar power and fossiles/nuclear to supply their energy and to keep a patch above icefree. I'd expect them to have many greenhouses with cold adapted plants sitting on the ice surounding the city.