Hi, I will be in Georgia for 5-6 days in early February. While I plan to spend most of that time in Tbilisi I would also liketo spend two days/one night elsewhere. So far Batumi is catching my eye though I'm a little apprehensive about the distance from Tbilisi. Is Batumi worth it? As an alternative, would you recommend Svaneti in winter? Other than that if anyone has any other destinations in mind I'm all for some advice.
Mtshketa ancient town and cathedral is the best choice for only 5 days staying in Tbilisi I guess.
Although, if you aren't afraid of overnight trains then Batumi is possible, it needs a night by train to go there and the same back.
Svaneti is one of the most gorgeous places I've ever been (I visited in early winter), but it's a bit too far given how little time you have. Kazbegi would be much more accessible if you want to take in some mountain scenery, but it's not nearly as beautiful as Svaneti. The suggestions of Gori and Mtskheta are good, and easily visited as day-trips from Tbilisi. Tbilisi and its surroundings have more than enough to occupy you for 5-6 days. Save the mountains for another trip when you have enough time to do them justice.

I would say Kazbegi (with a stay of 1 night there), and/or a day trip to Gori and Uplistsikhe (which is very special!).
Matthijs
Kakheti and Mtskheta can be easily visited even as day trips from Tbilisi.
Batumi is nice in summer. This time of the year it's not worth making such a long detour. For Svaneti you'd need more time as it's a whole region with several spots worth seeing.

Thanks for the replies, I will consider all the mentioned options and pick something that suits me most and is not too far.
Another suggestion - you can also go to Sighnaghi (Kakheti region), spend a night there and go back.