proof of funds

My bf got a TRV last year to travel with me to visit my family over the Christmas holidays. When we were going through customs/immigration we had separate declaration cards but went up together. The customs officer didn't ask us a thing about money. He simply asked him what's his status in Canada. He replied visitor. He checked his passport/visa then checked mine. I'm 95% sure he didn't even ask us where we were staying. It really wasn't a big deal at all. I would have the letter of invitation ready in hand just in case they do ask and you can prove that accommodations/ transportation are paid for by mother in law. It really shouldn't be an issue.