China vs Mongolia

China's $1,100/mo monthly cost (across 5 scored cities); Mongolia has no monthly cost data yet — not enough data to call a winner.

China's 3.3/5 safety score (across 5 scored cities); Mongolia has no safety score data yet — not enough data to call a winner.

China's 3.3/5 mobility score (across 5 scored cities); Mongolia has no mobility score data yet — not enough data to call a winner.

China's 3.5/5 culture score (across 5 scored cities); Mongolia has no culture score data yet — not enough data to call a winner.

China's passport reaches 52 destinations visa-free to Mongolia's 35 — China opens more doors without a visa. Passport strength shifts over years of naturalisation, not months of planning, so it's a long-horizon footnote — not scored in the tally.

China's 755M passengers/yr annual passenger volume (across 18 scored cities); Mongolia has no annual passenger volume data yet — not enough data to call a winner.

China runs -10°C to 37°C for most people; Mongolia runs -36°C to 29°C for most people. Harbin runs colder, at -34°C. Depends on you — which range fits your tolerance is the real question here, not a score.