If you have electricity, I'd suggest putting in a small vent to move air around/out while you aren't there. A tiny fan that pushes ~5-30 cfm out through a vent in the platform or crown ring would probably work well. Such fans are available in many different voltages (115 Vac or 5/10/12/24/48/etc Vdc). Owing to the small amount of power such a vent fan would require (1-5 watts), 24/7 running would take only 20-50 watt*hours each day-->a small solar panel with a small battery would run it nicely.
If you don't have power, a simple vent of some form or another might help. Getting it to actually draft well might be tricky.
I've a 20 ft traditional yurt with just a heavy canvas cover--I'm planning on covering it with lumber wrap (thin woven polyethylene tarps). This should shunt most of the rain (and UV rays) off the yurt, reducing how much water gets to the cover and insulation
There are a few other tricks for reducing humidity--dessicants (charcoal, zeolites, silicon dioxide, CaCl2, etc) left in a bucket to pull moisture
out of the air. But I'm not sure the cost/effort would payoff. Giving it a good warming when you first get there with the wood stove will probably help a lot, like cmwingfield said.
You didn't mentioned if you installed a semi-permeable vapor barrier (house wrap/tyvek) in your doubly-insulated yurt...