frequent travel on B1 while H1 is unstamped

[swati mp]

Consider this case please - my h1 is close to expiry (another 6 months to final death), my employer has just started to process my green card application, but of course, there isn't ample time for me to continue in USA. So I plan to move to Canada till the time the I-140 is available. Meanwhile, due to nature of my job, I need to travel occasionally to US. I have a valid B1 visa.
My question is, how many trips of what duration each do you think it is safe to make to USA on a B1 visa, whilst my green card application is on, and also where my H1B is still valid but not stamped? I say H1B is valid because if I move out now, I can again recapture some time on it.

[kabkaba]

Rule of thumb is before you return in B1/B2 status, time spent outside = 2 times the time spent in the US in the last trip
If you travel to Canada, carefully preserve evidence of your travel (Air Tickets, Passport stamps and any other evidence of road travel)

[swati mp]

Thanks, is this rule of thumb an accepted standard by travellers, or recommended by USCIS?

[kabkaba]

It is a rule of thumb.