Hi Serge,
Your current 1.3 mbps down / 600 kbps up is in my opinion quite low. It may work as long as it doesn't drop down too much below that. It would help if you could have the same ISP at both ends, for example if Bell.ca is your ISP at your cottage consider using Bell.ca at home, too.
My ISP at the radio site is a Wifi ISP and my latency is likely worse than that of your DSL. I'm not sure what the actual download and upload speeds are as I haven't visited the radio site in 8 months, but the Wifi ISP advertizes 6 mbps down / 1 mbps up. With my speeds (and latency) it is usable most of the time. Occasionally, when the internet at the radio site is likely experiencing slowdown, it does affect usability especially when sending CW.
When I was setting up my remote QTH, I was aware the slow internet could affect the quality of service, but the internet, in the longer term, would eventually improve. If I were you, I would suggest to think in long term. Even if the internet causes you problems now, a few years down the road it will likely improve.
73 Marvin VE3VEE