Sorry for your loss OP. It depends how much time/ energy and resources you want to put into it but it is possible to clear yourselves. We had to clear my granny's house the other year and managed to get quite a lot shifted without having to do too many top runs.
Definitely take all the paperwork and sort through it. Then ask everyone in the family to take what they would like to keep. Then you can start the sorting. We did 1 room at a time and then tackled the loft (which was a huge job in itself as my granny had kept loads of her mums old stuff when she died so we had all her stuff and all her mums stuff to clear).
Definitely make the most of charities. Not just the high street store kind who are sometimes more restrictive with what they take as donations due to space or volunteer time to sort donations.
Round us we have a couple of charities that help homeless/ women escaping DV/ vulnerable people set up their homes. They pretty much will take anything in half decent condition people need for homes -toasters, kettles, air fryers, slow cookers, irons, ironing boards, pots, pans, crockery, cutlery, clothes airers, curtains ect. We were amazed how much they were willing to take that we thought would have to be skipped.
We also have a furniture project who were quite happy to take tables, chairs, coffee tables and bigger furniture.
We have a community garden charity who were happy to receive the garden tools, plant pots, planters and bags of compost.
The local dog rescue took all the towels and sheets.
My granny had an awful lot of clothes from 1950s to before she died in 2019. Plus her mum's (nan's) clothes from the 1920s, 1930's, 1940's and up to the 80s. We sold a lot of the vintage stuff online and took some to the local vintage markets to sell to traders. Nan's 1920's, 30's and 40's stuff sold especially well as lots of re- enactors wanted them (her 1940's housewife stuff for a woman in her early 40s was very desirable). Another surprise was the real fur coats which again were very popular in the vintage market.
Put things like washers, dryers, beds on FB marketplace/ olio/ Gumtree and see if there are any takers. Our council charge to take big items and our local BHF can only take things in good condition with fire labels on them..
Any knick nacks that could be of value to the auction house.
Old photos, see what family members want to take, then anything related to social history - factory worker group pictures/ old school photos / old photos of buildings in the local area ect. can sometimes be of interest to the local history group. Our local history group are really happy to receive factory worker/ mine workers group shots from the various factories and coileries around us, especially if they are labelled with a year.
Then it's a real matter of been brutally honest with what is saleable and what is sentimental and if it really isn't saleable then it needs to be put in the tip.
Good luck with it all.