interesting that some of you leave your panniers on the bike, Ive always had them in the tent with me, having my things with me for the main reason, but also I dont see the time saved not taking them off (literally seconds) worth worrying about them being taken by some jerk, even if the bike is locked. I guess if your tents are that small, but usually there is some kind of vestibule.
Everyone is different. For me the reason for leaving the stuff on the bike was never the lack of space or the effort of bringing them in. I just don't have any need for most of my stuff in the tent at night. The theft worthy stuff is mostly in the handlebar bag and that does go inside the tent. The remaining stuff I am not all that worried about and in a pannier on the bike is better than laying scattered on the ground.
On my last tour I stopped using panniers and instead used ultralight dry bags. The complicated the choice because it was extra effort to put the stuff back on the bike and I have to take it back off in the morning to pack the dry bags any way. Still nothing went in the tent because I didn't take a tent. So the stuff laid on the ground next to my bivy, under a tiny 5'x5' tarp
if I pitched it. With 14 pounds of gear I probably could fit it in the bivy with me, but never have.