Dave, yes it is OK to use the spacesaver until you can get the main wheel tyre replaced, however, that means like AS SOON as possible, not at the end of the holiday!!!!
Space Savers are , imo, a complete pain and make more problems than they solve. I could not get a replacement tyre for the space saver on my Espace, and after a lot of argument with renault, they supplied a steel full size wheel as a spare. If you have the depth of recess to accomodate a full size spare, (try fitting your space saver and the wheel you take off, see if it will fit in the spare place), then it is worth thinking about changing the type of spare for one of the same as your main wheels.