No, Only short trip for a week or two might be acceptable. They ask for sponsor residency questionnaire (and passport pages copy) at any time and if sponsor has been outside Canada then they refuse the application. However I know in few cases sponsors are regularly visiting spouses for up to 3 months or more and they are making multiple trips of the same duration. Again now it depends on Visa office if they realize that processing time in Pakistan is too long and applicant don't get visa for Canada easily so this situation may be ignored. But usually they go by the book and its a high probability that the case will be refused. I know even some cases refused for same reason (not maintaining residence in Canada) where sponsor was a Canadian citizen. For PR sponsor cases its way much tougher.
According to the IP 2 Processing Applications to Sponsor Members of the Family Class manual,
"13.2. Residency requirements for sponsors
In assessing residency requirements for sponsorship purposes the IRB Appeal Division ruled that a sponsor must maintain a significant connection to Canada.
Officers should consider whether the prospective sponsor:
• maintains a residence in Canada;
• has spouse and/or children resident in Canada;
• has assets in Canada;
• pays Canadian income tax on global income;
• visits Canada regularly;
• maintains investments, bank accounts, health insurance or club memberships in Canada.
Sponsors may be found ineligible to sponsor if:
• they maintain residences in two countries at the same time;
• they have a house in Canada, but work abroad;
• they have interrupted their residence in Canada or spend little time in Canada.Foreign stamps or post marks on the envelope, a foreign employer or the sponsor's non-Canadian address are indications the sponsor may not be residing in Canada;
• there is evidence that they will leave Canada soon after the sponsored applicant becomes a permanent resident. Sponsors must satisfy an officer they will continue to reside in Canada after the member of the family class becomes a permanent resident;
• sponsors are not ineligible if they take short holidays or business trips outside Canada."
and
"23. Suspension of processing
If any of the situations noted below occur, processing of the application must be suspended until the matter is concluded, whether at the time of sponsorship application or if such information becomes available at any time during processing.
Reasons for processing to be suspended include:
• citizenship is in the process of being revoked (see section 23.1);
• the resident is subject to an A44(1) report (see section 23.2);
• serious criminal charges have been laid (see section 23.3);
• an appeal of a decision on residency obligations is outstanding."
and
"23.2. Permanent resident subject to an A44(1) report
Reasons for an A44(1) report on a permanent resident include:
• security grounds, human rights violations, serious criminality, organized crime, misrepresentation (e.g., failing to declare all family members on the application for
permanent residence)
• non-compliance with conditions of residency (e.g., entrepreneur)
• non-compliance with residency requirement
If the sponsor becomes the subject of a removal order, the removal order is a bar to sponsorship.
If an officer, either in Canada or at a visa office, uncovers information that could lead to an A44(1) report, the officer should contact CPC-M. Staff there will transfer the sponsorship to an inland CIC for investigation. The inland CIC should keep CPC-M and the visa office informed of developments on the A44(1) report and make every effort to have a decision on the report rendered as soon as possible."
