Sometimes you just get the greatest idea too late to be executed. It needs preparation, planning and practise. Or just something you need to order from overseas.
If the idea is still good it doesn't necessarily need all those. Just put your creativity to work and come up the way to realize your idea, no matter if you have the best possible options available. If the idea is good it doesn't matter. It's the thought that counts. And it definitely is better than nothing.
It can even be better that way. For example it can inspire a story of it's own. You can tell how you originally planned it but why you couldn't, how you improvised and replaced those things you were missing with what you got. It can make your idea more interesting and memorable. It shows that you have really put an effort to make it happen despite the situation.
Sometimes you can work on your idea later to make it better, closer to original. But sometimes you just have those now or never situations. In such situation just do as much as you can and improvise the rest.