I hope this is in a wild area of your garden Mark, and where there are no other cultivated plants. They self seed and spread by bulbs too, which burrow deep as they mature. They are tough old things, I would imagine now is OK. I still have to plant some saved tulips. Our native bluebell is best, with the bells on one side of the stem and a more intense blue. Nonscripta I think its called.

I would be wary in the bed you showed us earlier Mark. BB's are shade/woody area lovers and spread, the bulbs grow big, and multiply, not ideal for a mixed flower bed? The problem also is they are very scruffy once the flowers stop. Mine are in a woody shady area and can do what they like. If the ground isnt frozen you should be ok planting them. You might want to check if you have Spanish ones as these are real thugs? Perhaps putting them in a large container?

i put my bluebells in containers and they did quite well ~ better than in the garden i think and mine is a shady woodland garden!
it cant hurt to try mark??? i once planted daffodils in january ~ they still came up!!!