I wouldn't be moving the service. The house panel stays where it is. You run a totally separate feed to the garage only. It wouldn't tie over to the house. 60amp won't be enough. A welder on a 50amp breaker, a heater on a 30 amp breaker, compressor on a 15 or 20 amp breaker, all the lights, power tools etc... 60amp is pushing the limit.
Those are all cyclic/non-continuous loads. Aka they aren't constantly drawing all that load, that's why your stove says it's 12000+ watts, but you can get away with wire that's good for 50A.
You won't be using all of that at once. You don't straight up add together amperages of loads to find a demand factor.
It sounded to me like you wanted your 200A panel in your garage, then to feed your house off of it. Apologies..this is what happens when I reply quickly when at work.
AFAIK you cannot have two services in a residential setting, if you can, it would probably cost a **** ton to have hydro come out and bring a second set of service conductors to it. I'll quote the CEC on this.
6-102 Number of supply services permitted (see Appendix B) (1) Two or more supply services of the same voltage shall not be run to any building, except that additional supply services shall be permitted for supplying (a) fire pumps in accordance with Rule 32-204(1); (b) (c) (2) industrial establishments and other complex structures; or completely self-contained occupancies where the occupancies (i) are not located one above the other; and (ii) have a separate entrance with direct access to ground level. When two or more supply services are installed to a building, all service boxes associated with the various consumer’s services shall be grouped, where practicable. (3) When two or more service boxes installed in accordance with Subrule (2) are not grouped together, a permanent diagram shall be posted on or near each service box indicating the location of all the other service boxes supplying power to the building.
it uses the word "occupancy" which the CEC defines as "Residential occupancy — the occupancy or use of a building or part of a building by persons for whom sleeping accommodation is provided but who are not harboured or detained to receive medical care or treatment or are not involuntarily detained."
You can get subpanels larger than 60A obviously, but I doubt you'd need one.
Do a service calc for your house, including your garage loads (you could probably just do one for your garage) to find your service/subpanel size.