You can not turn the heat down too low unless you freeze pipes. There is a very common and untrue legend that it takes more energy to bring a space back up to comfortable temp if you set it too low.

Stuff a throw rug under the door to keep the cold air out. Think again, are there any pipes near that room?

No pipes near that room but I will have to try to stuff the underneath of door with something.
Thanks for the reply.

I still need help with this. Any other comments.

lyban

tell us about the type of electric heat you have.

how many degrees of setback do you program while sleeping?

in general,I have always found a large setback at the thermostat for electric heat is a poor cost saving strategy.

FROGs known as "finished room over garage" are notorius for even cooling and heating. This type problem is usually an indication of poor insulation and/or ductwork design sizing. I have never liked the idea of closing vents and the door. if the draft is such an issue, I suggest installing some electric baseboard heat to temper the air in the room.

While you describe this room as a guest room, I will assume it is unusable due to the cold condition.

I just don't know of an inexpensive method to solve your problem.

Sorry.

IMO

You can also buy little tubular sacks that are built for blocking drafts. Google draft and pillow or blocker. Here's one to give you an idea of what I'm talking about:

http://www.kohls.com/upgrade/webstore/product_page.jsp?PRODUCT%3C%3Eprd_id=845524892531610&pfx=pfx_shopcompare&cid=shopping3&mr:trackingCode=5B378605-2FC6-DE11-974B-0019B9C043EB&mr:referralID=NA

As for setback, I would go no lower than 55, and then consider how long it takes to get your house back to temperature. Not much point in setting back if you're frigid. Also depends on what temp you like to sleep at.

For me I set back to about 64 at night, 70 for when I'm home.