That's what I do. When I open a can of pumpkin and use one glop, I put the rest into sandwich-size baggies (one glop dose per baggie) and freeze it. Next time I need pumpkin (well, the dog needs the pumpkin) I get one frozen dose out.
Patti--that will be exactly like canned pumpkin, only fresher and made with love. You'll need to cook it first. You can bake a pumpkin whole, then cut it in half, scrape out the seeds and mash the cooked flesh which will be quite soft. Or cut up and peel the raw pumpkin and cook the chunks of flesh. Bake until they are soft. Just like you'd cook any squash.