South Korea mamas, please help; trip planning.

[mrseum]

Hello! We're finally going to South Korea so the baby can meet his grandparents! I'm super excited. But I have few questions... does anyone EVER have a stroller? We'll be using my FIL's car, but also the subway and taxis, and we're going in January. I have a beco butterfly carrier I'm going to bring, but he's already 19-20 lbs at 6 months, and he gets heavy quickly. Not to mention I'll have a diaper bag and then whatever bags from shopping... spending all day out like that is going to be extremely hard. So I was wondering about taking an umbrella stroller. Would it be worth it, or just a really bad idea? I mean, getting on and off the subway would be difficult. Then if it's snowing outside while we're trying to get to our destination it's just going to be one more thing to carry. However if we're in a store I'll be able to put him down for a bit and put my bags around the handle bars. Any advice?? I wish someone would create a collapsable umbrella stroller that folded up as small as a more compact umbrella!