Ok, I have another solution to this that doesn't require you to wait for 5.5 nor does it make you set a global setting, but it does require you install a plugin, at least until I can get this merged into core. You'll need the timelion-extras plugin from here:
I added support for date math to the moving average function. So now you can do something like:
.es(metric=sum:bytes_per_minute).mvavg(1m)
This accomplishes the same thing as that blog post, except it also works if the low buckets have data in them. In the case that the interval is smaller than 1m, this will average all the points over a minute. If the interval is over 1m, it won't do anything, the series will remain the same.
In action:
