Day trips only. I would go with a mate who has lived in Laos for nearly 15 years. We'd take only take bottled water because food (usually noodles) and snacks can be got in any village. You can also buy petrol in most villages as many villagers have motorbikes. We base ourselves in Luang Namtha town at a guest house which hires out motorbikes. One loop we ride is about 100 kays. Some roads are sealed, some aren't. We'd normally go in June just before the rains really set in. Being at highish altitude (around 1000 to 1500 metres) it's not as hot as in the lowlands. November to February the nights can get to zero in the mountains. I've never felt fearful or felt threatened and people are friendly. Language barriers is the biggest obstacles but generally we can make ourselves understood. Most don't even speak Lao language in these remote areas.