Possible to limit tag cloud to include only tags used in most recent n posts?

Is there a way to limit a taxonomy list or tag cloud to only show the last n (say, 100?) posts? I’ve got a site that has content going back to 2002, and the tags I use now are more relevant to readers now than the ones I was writing about back then. I can see how I could set the range to show just a certain number of tags, but not how to set it to show only tags from the most recent 100 posts.

I’m using Artem Sidorenko’s technique to generate a log-weighted tag cloud.

This is not tested, just walking through how you might do it:

1. Get latest 100 posts:
{{ $latest := first 100 (sort (where site.RegularPages "Type" "posts") "Date" "desc") }}

2. Get the tags of the latest posts:
{{ $tags := slice }}
{{ range $latest }}
    {{ range (.GetTerms "tags") }}
        {{ $tags = $tags | append . }}
    {{ end }}
{{ end }}

3. Remove duplicates
{{ $tags = $tags | uniq }}

4. Render list 
{{ range $tags }}
    do your magic here
{{ end }}