It's easier than you think. You'll have to place further restrictions on yourself if you want to make it a challenge, like limiting the number of your 'home' provinces. Extermination produces more funds than occupation, and with a 10 province France I had few problems occupying all cities, releasing all prisoners, and leaving all of Europe to the rebels in the Total Independence campaign.

There are some technical hurdles to overcome, but I'd suggest doing this as the Mongols. As a Horde faction you can literally burn every settlement, and your limitation is the fact that you only have your starting armies, no new training.