a good way of getting a ring off is to wrap the finger in cling film just below the ring as tightly as possible then grease up the finger and slide ring off or failing that wrap tooth floss tightly around finger and do the same thing
For your question can you get it made bigger, yes, the jeweller can put a piece of gold/silver into the band and make it bigger without looking any different. Alternativly, they can stretch the band itself, using the gold/silver thats on the band to 'stretch' it.
a good way of getting a ring off is to wrap the finger in cling film just below the ring as tightly as possible then grease up the finger and slide ring off or failing that wrap tooth floss tightly around finger and do the same thing
Along with the above hold your hand in the freezer for a few minutes as the cold will make the fingers smaller. Same as heat makes them expand slightly.