From Dec 2016 - March 2019 we lived with my parents, and we have NHS letters, credit card statements, a police report for my insurance claim, insurance letters, payslips, letters from employers, P60, NI registration for partner and letters from other misc. registered companies - the only issue is these are few and far between. (i will update this post tonight with a timeline to reflect any gaps!)
From March 2019 - now we rent our own home, have a tenancy agreement, council tax bills, utilities, credit card statements, NHS, notification from home office of updated address etc - so plenty all crammed into a small period of the 2 year window...
I have also now turned off all paperless billing and set up a filing system for the next application, but for this one im absolutely bricking it and the potential financial loss of messing up is keeping me up at night