Have you ever grown large bulbs in a container?

Yes, I have done this and it works very well. I live in Ireland, but have lived in Portland and the SF Bay area so have an idea of your climate which is probabl;y fairly similar to my own. I don't bother bringing the bulbs under cover in the winter, just give them a heavy mulch. One thing you may or may not know: lillies have a pollen on their stamens that can be toxic to cats. I make sure my pots are placed where there is no chance the cats could rub against them.

Here in the UK it's not always easy to grow really good lilies but I have a couple of large ornamental pots in my back garden which is south facing and gets quite warm in the summer. I managed to get three bulbs into each pot last year and they looked stunning when they bloomed.

i suggest you a few tips that might be of great help to you: when you flower bulbs in container drainage is most important, make holes at the distance of 6" at the bottom of your container and cover these holes with shards to prevent soil from blocking the holes after watering you can use either soil or even garden compost here you can plant blubs closer than u plant in garden, however they should not touch each other or walls of container, plant them 5-6" deep when bulbs are large and 2-3 inches for small bulbs protect them from frost, cover them with insulating material or pine branches, and always water after planting

Geography sure isn't my thing, but what kind of winters do you have? I think lilies are a perennial that need overwintering in the ground. I've tried leaving bulbs in pots over the winter and in the spring they are usually "mush" and rot. Maybe the container was not large enough though. Anyway, I have grown amaryllis bulbs indoors (they grow themselves really, lol). They would just as successful grown outdoors in good weather alo. However they don't have the scent that lilies do. If you are just thinking of growing the lilies in the pot for one season I'm sure you'll have success with them. Yoo will probably have to stake them though so they don't fall over and snap off.