regardless of it being room-sealed I don't believe you can have a woodstove in a room which has an extractor of any kind. Read the B-Regs very closely for your jurisdiction...
there was certainly a massive range of levels of completeness and support when we were dealing over ours. I'm really glad we went with our second option. @Kevan Marshall drop me a PM if you want an overview...
one could always try not even moving the thermostat but just turning it up a few degrees. Wherever the tank is will still track the rest of the house, even if it's a wee bit higher...