Hi Sprout. I used to live over the border from you in Manitoba, then in T.O. Don't know what sort of a winter you have had, UK has had its worst in 31 years but nothing like a true North American job. I reckon you should be pretty safe if the ground has thawed where there is no straw. Tulips are pretty hardy as long as the bulb itself doesn't freeze.

Thanks----I also planted some strawberry's last summer and covered them with straw .Would it be the same answer with them also ? Can I leave the straw on too long for ether of them ?

Same answer. You can in theory leave the straw too long but it probably won't do a great deal of harm. They may become forced in the dark under the straw if it is thick but its not a great concern.