We always hook one into another, all the way across, we use the mini lights, with ext. cord on one end to plug in. Never had any probs. with it.

We use multiple extension cords. If we do a lot, then we use two different plugs as well. This year we only put a few strands up. I think the most that are connected are 3 strands. It also depends on how many lights are on each strand I believe.

Depends on the lights and the cords. The LED lights, with their low power consumption seem to allow more cords to be connected, however they also are rather lightweight cords on them too. Check the boxes or the labels on the cords and see what they suggest. Risking a fire is foolish to save an extension cord or two. You can often plug several into a heavy duty outdoor cord.

I'm also careful about what sort of clips are used to hang lights. They can easily fray the cords.

We have 5 strands hooked together. Been doing this for years. No problems.

My husband's outdoor decorations are extensive. Takes him about 2 weeks to get them up. We do use a lot of extension cords, we have extra circuits in our circuit box that are JUST used for the Christmas display.

I know my husband hooks many more than 2 strings together and we've never had a problem. But you really do have to make the decision for yourself. We're super careful with our display, never have it on unless we're home to monitor it. And DH works for the power company, so he is familiar with working with electricity.

We don't have lights up this year but normally we outline the house roof(s), it takes 6 sets of the old fashioned big lights...are they C9s? In addition we hang a 6 foot wreath and a 7 foot star. Our wiring is set up that the holiday lights plug in to the same circuit that run the pool and ponds in the summer.