Welcome to GoY.

You should be able to grow new plants from seeds/pips but they may not come true to the original tree that your
great granddad planted. But the nice thought is that they are from your ggdad's tree.

Is there no chance that the tree can be saved? Was it uprooted or just had branches torn off? If partly uprooted then it can be righted/propped so it doesn't move any further. Any damaged branches need removing and then the tree will continue to grow on the remaining branches.

in our old orchards here in the UK you often find trees that have been storm damaged in the past still fruiting well.

Good luck.

You should be able to pick up a couple nice size pear treas from the garden center at The Home Depot or Lowes or simply order a couple online. Growing pears from seed is an interesting project, but don't expect any fruit for at least 8 years - I mean nice tasty pears you can really enjoy. I say get a couple trees because they do better when they cross pollinate - a greater yield, a tastier yield and stronger healthier trees. The bees would love you too.

How about taking cuttings from it?
Worth a try at least.
And by chance here's a chap who did just that with a grandfather's tree.
A search for taking pear cuttings will throw up loads of results

https://www.youtube.com/watch?v=cnddsRJEd8M

PS, the apple tree of Isaac Newton fame has been propagated by cuttings, so definitely worth a go

https://www.bbc.co.uk/news/uk-england-leicestershire-43385897

Yes, probably cuttings wold be the way to go - any fruit you eventually got from a seedling could well be small and very disappointing. If there are some viable branches left on the tree you might try air layering a shoot or two while still in situ. There are videos on line to help you - good luck!

The original bramley seedling apple tree in Southwell provided the cuttings for the bramley seedling and all trees with that name are from cuttings as the pips don't come true from seed..
Sadly it is slowly dying but it was grown from a pip in 1809, yes 1809.