Warming tea for winter

Over here in London it's starting to get very chilly. I've had to buy earmuffs and new gloves. Even a snood. They are all very useful in the cold and blustery weather. What I really want though, is a lovely warm cup of tea to sustain me on my travels.
I have a brilliant flask but it is massive and heavy. Far more suited to a picnic than a commute.

So I need to find something wonderful to cheer my ragged soul at this time of year. I need something that will keep my tea toasty and help me raise a smile on London underground. No easy task!
Does such a delight exist? Just large enough for one cup would be perfect.

So what does the market have for me?

Here are few considerations:

The Bodum Travel Mug

This little beauty comes in a whole host of colours and is available at lots of high street stores, but isn't it basically a thermos flask?

ANOTHER Bodum travel mug - this time with a handle! Both claim to be spillproof, and this one looks a little more stylish to my eye, but I'm still not convinced they're up to the task of actually making me want to drink tea on the tube.

This one isn't spillproof; a porcelain version of the paper coffee cup. I'm not sure why this is considered a design classic, it doesn't really grab me. Kudos for the funky patterns though.

This one describes itself as the perfect travel mug ever, and surely it would know? The Brugo is different from the others in that it has a 'sip chamber'. It also claims to be spillproof.

It would be unforgivably remiss of me not to include Thermos themselves. Of course, they produce all manner of options.

If anything this little exercise has left me even more confused. I think I basically want a cup and saucer, and that's frankly ridiculous. What would I look like? Some kind of Lady Gaga wannabe? And there'd be tea and porcelain everywhere. I'd get all sorts of tuts and tsks. Someone might even huff at me. Well we can't have that. So no, I won't go for a cup and saucer, it's too risky.

So what to do? What to do? Why aren't there amazing wonderful, jump-out-at-you-brilliant mugs?

Does anyone have the answer?