Legal bit before doing the wedding

We are debating whether to do the legal bit before then the wedding at a later date, for context we have chosen a date that means a lot to both of us because its both of our grandparents wedding date, with their blessings were thinking of doing legal bit with them because of their health and cant travel and then have our little wedding after, but would you plan to do it before your chosen wedding date the year after or on a random day? our day will still be the same date legally as we would go by that date? its not going to be a big wedding either, just 10 guests and us then having a big party when we are back thanks in advance