31 months seems to be the worst case scenario - I am not sure about the 1 year but 16 - 18 months should be reasonable but it's all subjective and there are many factors that influence it.
You can certainly apply for a visit visa (TRV - temporary resident Visa) - I would suggest you post in the visitor's section of the forum since a lot more people with TRV experience will be able to advise you there.
The thing with TRV is that it's hard to say whether a certain amount of money is sufficient for your application to be approved - We've seen people with worse applications getting approved and better applications getting denied.
The key to obtaining a TRV is to convince a visa officer that you will return home after your allowed stay expires. You can do that by showing ties to your home country like a stable job that you have to come back to, a property in your name, any family associated with you that you have to come back to.
The funds seem sufficient - the letter of support from you father in law is great as well. But I will focus more on showing your ties to your home country.
Also, (and maybe this should've been the first point), be honest in your application. Tell the visa officer why you need a tourist visa. Tell them that your PR application is in progress. provide PR file number. Tell them that the current processing time is 31 month and that its taking a toll on your marriage etc etc.
Again - I don't know what the magic criteria is. I always think it's on the mood of the VO whose desk your file lands on. My wife got a 4 yr multiple TRV and she had Rs. 20,000 in her bank. And there are other people who show thousands of dollars get denied.
In short, focus on showing ties to the home country and explain honestly (and emotionally) why you need a TRV.
All the best bud.
P.S: post in the Visitors section for the TRV
