Is the Western Mountaineering TerraLite a realistic choice for Alpine bivies from June to October?

Hi everyone,

I'm fairly experienced with hiking in the Alps, but this year I'd like to start doing more alpine bivouacs. I recently went to a specialized outdoor store, where they recommended and sold me a Western Mountaineering TerraLite.

Now I'm wondering whether that was actually the right choice, and I'd love to hear some opinions from people with more bivy experience.

My typical season is June through September, with August and September being my main months. I'd also like to do the occasional trip in October, but those would definitely be much less frequent.

Most of my trips are in the Austrian Alps, mainly in Salzburg, Upper Austria, and Styria.

For reference:

• Male, 25 years old
• 190 cm (6'3")
• 75–85 kg (165–187 lbs)

The most challenging destination in October would probably be Raucheck, where the average coldest October night over the last few decades is around -7°C (19°F).

For sleeping pads, I currently have an Exped FlexMat Plus (R-value 2.2). I'm also planning to buy a NEMO Tensor All-Season (R-value 5.4).

I know that these October conditions are probably close to the lower limit of what the TerraLite is designed for. The staff at the store told me that going with a warmer sleeping bag would probably be overkill because I'd likely overheat during most of my trips and would carry unnecessary weight. Their recommendation was to use the TerraLite and for the occasional colder October bivy, simply wear my down jacket and a very good hat, tube scarf, gloves etc.

Do you think that's reasonable advice, or would you say that's pushing the TerraLite too far? In general, do you have any tips for comfortably extending its usable temperature range? Besides wearing a down jacket, are there other things you'd recommend (down pants, a warmer sleeping pad, a sleeping bag liner, eating before bed, hot water bottle, etc.)?

I'd really appreciate hearing from people with experience using the TerraLite or doing alpine bivies in similar conditions.

Thanks!