The EU works by restricting certain things to within the group they believe this benefits all their members. They want to trade with other nations and have already said they will offer this to the UK freely. These other nations would have wanted more access but an agreement could not have been reached. The UK want additional elements currently only open to the members of the EU to which the EU don't want to give up this is the preferential part.
I have given a few reasons why others would wish to follow, you may not agree that others will follow suit but this is the position the EU negotiators have said they will go into negotiations with so our opinion is a little moot.
Canada is not a close proxy as it does not involve services which is the key thing we require so far the EU have kept this within the Bloc. Reading up on the Ukraine there is an agreement but no deal has currently been signed as the Ukraine must achieve a number of political goals. As far as I can see the DCFTA deals that have been agreed are a step towards membership - Also it appears we would be closely bound to EU law which leave the tricky question for Brexiters and Soverignty
http://www.independent.co.uk/news/l...it-deal-no-one-is-talking-about-a7895861.html
What we want does not exist and has never been offered by the EU, we want more than others are getting and so far the EU have not been willing to offer this.