Seek, I add my congratulations to those already given by Paul.
I think from what you post that you intend to get married in the UK. Right? You talk about going back to Canada to apply for a visa there, so I think you mean the marriage to happen in the UK. If that is correct then that is entirely possible but as a non-EEA citizen you will first need to apply for, and get, a Certificate of Approval to Marry ("CoA").
Click here to download the application form. Get that completed and submitted as soon as possible. It will take about two months to get your CoA, and after that the two of you need to go along to a designated Register Office and give the needed Notice of Intention to Marry. Only 15 days after that will they issue the needed permission to marry, such permission being valid for 12 months. In other words given that it is valid for so long, get the CoA application and Notice of Intention to Marry out of the way as soon as you can.
Following the marriage in the UK you can then apply for a 2-year spouse visa
in the UK. There is no need to wait until near the end of the current visa. You can apply as soon as the marriage has happened. You will use form FLR(M) to get that visa. Then near the end of the resulting 2-year spouse visa, you will apply
in the UK for ILR.
Applying for Naturalisation as British? Assuming you have ILR by then, you can apply for Naturalisation any time after three years in the UK ... counting from when you arrived in the UK on the WHM visa! Oh, but you will need to pass the Citizenship Test before making that application!
Seek, if I was wrong in the assumption about the marriage in the UK, and instead you plan to get married elsewhere, for example in Canada, then let me know and I shall post the differences that will make.
Oh, and if you intend to get married in the UK, but in a
Church of England Church, when let me know that, because that will also change the procedure a bit.
I'm trying desperately to find a way to keep the time we're apart to a minimum.
There need not be
any time apart!