Why dont you just bike around La Grande right now? When its YOUR winter? Why go all the way to New Zealand for somebody ELSES winter. Maybe because in La Grande it easily drops into the teens with snow to match, whereas in New Zealand youll generally be above freezing.
Anyway, several tents will work. First, though, the philosophical stuff. Weight matters a bit less when biking because you have a better mechanical advantage thanks to the gears. Thats especially true when pulling a trailer; its easier to haul a load in a trailer than to load it on your bike. But sure, weight matters. Especially if you want a tent to take hiking. The other thing is, tents really arent warm," as such. They simply have more or less ventilation.
So, if it were me, Id probably take a Black Diamond Lighthouse ($379; bdel.com). Its a three-season tent that seals up well enough for blustery weather, and it weighs only 3 pounds, 12 ounces. It can fit two people, meaning youll have lots of space for yourself, or room for a guest, should you need it. Its a light, single-wall tent made from a material called Epic, which is a little bit breathable and offers plenty of rain-resistance. Itll work great on your bike trip, then make the transition nicely to backpacking.
I also like Marmots EOS 1P ($225; marmot.com), which is a solo three-season tent. Its a more traditional designyou pitch the canopy, which has some mesh in it for ventilation, then you toss a fly over that to keep out rain and some wind. Its even lighter than the Lighthouse, around three pounds, which is fantastic. Its smaller, of course. And it might be a little drafty when the wind is up and temps are near freezing. Then again, you should be able to find sheltered spots in which to pitch it.
For a really, truly weatherproof tent, take a look at Mountain Hardwears Spire 2 ($425; mountainhardwear.com). Its a true mountaineering tent with very rugged construction, a full-coverage fly, and a canopy that buttons up tightly. Weight, at five pounds, is pretty good. But I think its more than you need. Really, Id take a Lighthouse.
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