> Is there any more elegant solution to bring water with me at a
> reasonably hot temperature so that I can at least make a few infusions
> without having to re-heat my water?

Buy a good thermal carafe and that should keep your water reasonably
hot. Chinese have an obsession of only drinking boiled water. So many
families store their boiled water in thermal carafes. Then, they can
have hot drinking water on hand whenever they need it.

The trains here all have a water boiler in each car. And each
compartment has a thermal carafe for handy storage of hot water.
Except the water temp. varies depending on which train you take! The
train from Guangzhou to Beijing has rather mild temp water - and
unsuitable for oolongs. Good for greens and scented teas though. The
train from Fuzhou to Shenzhen has really hot water - good for any
oolong.

You know, it's pretty hot here in Fujian in the summer. And on hot
days, we expect to buy ice cold beverages from the beverage fridge at
any store. Not so here. They store their beverages in those fridges at
room temperature!! So here, on a hot day, you only have a choice of
warm, or hot beverage. Never ice cold. The only thing they keep iced
is beer. Strange country.