It's an interesting question. I suppose it makes sense not to fill their inbox while they are away.
The execution of a "pause for n months" campaign is straightforward, but it would be a pretty manual process to identify these leads and put them into the campaign, which could be onerous depending on your list size.
If these are replies coming to sales reps, you could create a requestable campaign that they can activate via Sales Insight (if you use it).
SMART LIST
Campaign is Requested, Source = Sales Insight
FLOW
Change Data Value - Marketing Suspended = True
Wait, n months/days/etc/
Change Data Value - Marketing Suspended = False
If you wanted to be even more personalized you could try creating and having your reps populate a date field "Suspend Until Date" or something -- use the change data value on that field as a trigger, then use that field as the token in your wait step:
Wait until {{lead.suspend until date}}
Then after you reactivate them, send a welcome back/congrats email when they return 😉