Suppose you're away for a few weeks and Tesla sends out multiple updates during that period. Does it overwrite the earlier update or does the update RAM need to be empty before another update will be downloaded?
The way the updates work (usually) they send out a package containing files for all systems, the updater then checks the versions of each system and applies the update only if the package version differs. So if you skip one, the next one will contain all current code. You don't have to do them in order or anything.
Since I'm handicapped, I haven't been able to drive for the past two months, so I've been skipping the updates. I finally updated a few days ago, and the update went fine. So yes, you can skip updates.