yes. For your purpose, check out the tyvek options. A little google effort, some tyvek and tyvek tape, you get a water proof shelter. My boyscout nephews are doing this. For about 30-45 US dollars, you have a water proof sack that folds small. Look here. All I ask is post some pics. And no need to refer to me. Just reference the site you find. This site seems cheap, but there are others. I found one last year with 14x3 foot for 20.00 US. I have opted for silnylon because i am backpacking. You can cut tyvek to the size you want, then tape the seems. Quick and easy. One thing to note, most don't zip up to keep out bugs and crawlies, but it could be done. Tyvek tape is strong. Good luck. Just post one pic of the bike and your tyvek bivy on the site. Okay, a bit more. Do some reading. Condensation is a bit of a problem. I plan to put a bug net at both ends to mitigate (I perspire a lot). When it is cold, the condensation can be a bit of a problem but the heat retention is worth it. I plan, as stated, to put one pole that I found when hunting at the shoulder to drape it. I did this with painters plastic drop cloth last year in October in the mountains of Colorado. It worked well with a -20 bag. Actually, it was awesome, waking to the night sky vacillating between full moon and snowing. Okay, I have had enough scotch. I wish you safe and adventurous travels. I hope to get my own bike (2000 1150GS) back on the black top. So, your goals have inspired me.