Pre-planned--get community buy-in for a car parade--following a predetermined map/route--to look at homes that are decorated and end it at a local park or community center that has enough space to have large tables so kids can grab a pre-made bag of candy or treats on the way out or the bags can be handed out by masked volunteers right through the car window.
You could create a covered booth with a small window cutout to present sealed pre packed goodies (non edible) , or you could build different small stations in your yard with little pre packaged treat bags with things like colorful erasers, pencils, and mini size toys etc. These are non edible items. You can make fun signs directing them to the different treat stations. This will create non contact and the kids will feel like they are on a scavenger hunt!
Maybe kids going out for the night might not work this year. But we can still have some fun with our Halloween decoration that we put out in our yard or around our home. Skeletons can now dress up wearing a mask to protect themselves. Make Dracula and put a bloody mask on him with his teeth coming out of the mask. If kids can still go out for candy mark your driveway with a line like in stores and have kids stand in line for candy. Another great way is to have a Halloween block party where you set up a booth and a drive-by where kids can put their hands out the windows of the car to get their treats.
Our church has always been really big on Halloween as we feel kids are much safer in a more controlled area than wandering the neighborhoods.
In the past we have had a lot of entertainment and play activities as well as pizza, hot dogs, pop corn, drinks, etc so this year is going to seem awfully quite and may not keep the children off the streets.
We know that cars cannot come close enough for children to reach out of the window and take something from our hands (distance may not be enough either) so we're trying to come up with adults holding a pole/paddle with a small basket on one end and cars could be close enough for children to reach into the basket.
Maybe have several lines for different items.
Haven't finished this idea yet but it looks promising.
hope others offer suggestions that everyone can use.