It's not pretty, but you can get the indent smaller by tacking it onto the end of the previous item with some <br/>
's like this:
# Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
#:
# step 2 foobar<br/><br/>Now for the final step:
#:
# step t
Which comes out looking something like this:
1. Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
2. step 2 foobar
Now for the final step:
3. step t
The only other option I know of is to fall back to HTML instead of wiki markup for at least the 2nd part of the list so you can specify the starting number for the list, like so:
# Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
#:
# step 2 foobar
Now for the final step
<ol start="3">
<li>step t</li>
</ol>
But of course you need to maintain that final number manually if the list length changes in future.