I heard that government will rebate Solar Panels fees, my questions are, if that is true:
1- how much would it cost to install solar panels
2- how much electricity fees would it save?
3- how much does the government give back?
4- is it effective in the winter?

Which government? Federal or Provincial? Have you tried a web search?

The answers to questions 2 and 4 would depend on what scheme you were planning to get the panels under. We have solar panels, we are in Ontario and we are contracted under a system called MicroFit which I do not think is available right now. It cost $26k to install the panels (in 2017), plus another $5k last year to have them removed and reinstalled for new shingles to be put on the roof. We get $3-3500 per year in payments under the scheme. We still generate some electricity in the winter months, but obviously much less, especially if the panels are covered in snow.

The general consensus I hear is it's best to do it when you're redoing your roof anyway, since it works out cheaper to combine both jobs. That's what we're planning to do.

Hi, I am also in Ontario and have a 10kw system on my roof though most of the panels face W and the others S. We receive 38.4c/kw which gives us a little over $3k a year, installation costs in 2015 was $29k. I live in a bungalow and in winter I put up a ladder and use a roof rake to remove most of the snow if the forecast is for a couple of sunny days. I admit that the reward for clearing the snow is minimal but I love being outside in most weathers and clearing the snow makes me quite hot!
Another option you might want to look at if you are doing your roof anyway is solar shingles, they are much better looking, see pvtech.ca
A question though - my system is currently giving me an 'isolation error' fault which seems to be caused by a short circuit somewhere in the system. The original installer is not interested in any remedial work and another solar panel installation company say that because the problem is intermittent it'd be extremely difficult to find and fix. Any suggestions?

Our panels are on the highest section of roof that we have, so no way I am going to clamber up there to remove snow, sounds like we have a similar installation to you only ours mostly face south with a few facing west. Can’t help you with your error message, sorry.