A Norwegian insurance company did a map of all the places bikes were stolen in Norway last year. Every stolen bike happened in a large town or city (90% in large cities). I always buy food in small towns and villages and if I’m in a big city I will take my bike in to the supermarket. You really don’t need to carry a big lock with you.
At night if your bike is next to your tent It won’t get stolen unless you camp in a park in a city (which is illegal anyway).

I have in the past taken a hiplock to tie the bike up when food shopping. https://hiplok.com/product/zlokcombo1/

For something a bit stronger and still very compact and light:
https://www.tradeinn.com/bikeinn/no/ottolock-las-av-kabelbinder-cinch/137889470/p?utm_source=google_products&utm_medium=merchant&id_producte=12076404&country=no&gclid=Cj0KCQjw4NujBhC5ARIsAF4Iv6c65C0Hp8Apo44VKJM0uJhOFSFuxsLHqZbnE4hKkPzGfG-FLDru9OQaAg38EALw_wcB&gclsrc=aw.ds

In completely stopped bothering with locks in the nordic countries. If I camp in the actual wilderness I don’t bother at all with securing the bike in any way and I only take to the tent what I need for the night. It’s unlikely that someone would approach a lone tent that is respecting the 150m rule of the Allemannsretten. Might be a bit different if you camp next to a big road. What you can always do is attaching the bike somehow to the tent. Just run one of the guy lines through a wheel or the frame. If someone tried to “free” the bike it would shake the tent enough so that you’d wake up.
Another option (more for the grocery shopping situation) is to put a small padlock through one of the disc brake rotors. Would potentially damage your gear if someone actually tries to cycle away with your bike without spotting the lock first, but better that then the bike gone. What I usually do is to park it switched to the hardest gear, then (sometimes) I would attach it with one of my straps to some pole or any structure I can find.
Also consider that our bikepacking/touring cycles are not super appealing to organized bike thiefs, since they are often highly individualized or even custom builds, meaning they are harder to sell than off-the-shelf models.