Just think of your new setup as starting a new logbook; no need to type in every flight from day 1, just transfer over the important totals & add each new flight as it happens.
Of course this does depend on your software & how searchable you want your digital logbook to be. If you're handy with spreadsheets just make up a searchable xlsx & make your own search functions.
Any decent logbook software should have the ability to download a backup in a non-proprietary format.