Incidentally, double-glazing is frightfully expensive. With experience I would opt for the largest possible space you can devote to it, relative to other demands for living space and to budget available. If you are obsessive-compulsive as wine lovers tend to be, the likelihood is you will need a lot more space than you think. Think of the number of bottles you would like to keep, double it and then double it again, and you will not regret. However, avoid storing strong-smelling foods.
Wines pick up odours despite corks and capsules.
Having designed and used both, I would unreservedly recommend the below-ground option. Digging a big hole under your living room or in the garden outside is a major construction job. Not to be lightly undertaken, as it involves all kinds of other implications, such as moving out and staying in rented quarters for up to a year. If you have a swimming pool and have given up swimming, or do not have children who would enjoy it, or you do not like to get wet unnecessarily, conversion of the said pool becomes a simple option. The advantage of below-ground cellars is that the additional insulation provided by the earth around the four sides and under the floor significantly reduces the energy cost of keeping the cellar cool, by approximately 25 per cent which over the years adds up to a considerable saving as well as being environmentally more friendly.