D.P.
i would throw down sleeping bags and let them come in when needed. I have a sleeping bag on my floor all the time for my 3 year old...she used to come into bed a lot and it got to be too much because i would lose sleep. we did give her a reward for sleeping in her bed for 10 nights (took her more than 10 nights to earn it), but for now she sleeps most nights in her bed. if she does come in the middle of the night, she knows she has to sleep on the floor if it is too early, then after 5 or 6 i allow her to come in the bed for a snuggle. I still let my 6 year old sleep in our room occasionally during storms or if she is sick.
I would say for right now, it will give the kids comfort to be with you. You dont have to let them sleep in the bed, but i would guess they would be okay with the floor too just as long as they get to be close to you. Have it ready for them and tell them not to wake you.