I don't expect any kind of bubble during the regular season, but I fully expect one for the playoffs at this point and I think the players would have to agree with that as well, much as we all know they didn't like it the last time. It's the only chance of realistically getting the postseason done in a timely order.
Thankfully, for their sake, if we're assuming that the postseason itself would be more "normal", that meaning eight teams from each conference instead of last year's qualifying round + round robin add-ons, then we can look to last year and see the postseason-proper began on August 11 and ended on September 28. That's 49 days (51 if the SCF went 7) for the two teams that go the furthest, fewer days than that for teams eliminated prior to that. Of course, there is also the bubbling period ahead of time; I'm seeing last year's reporting dates were July 26 with the first competitive games (excluding the one-game tuneups each team had) beginning on August 1. So add an additional five days to that 49 number.
Either way, it won't be popular, but there's really not a good alternative otherwise. Either COVID protocols will decimate rosters entirely, cause dis-coordination with playoff series, and don't forget that what do you do in the third round when the token Canadian team is there? We can't count on the border being reopen, so the Canadian team will probably be stuck in the US for the rest of their run at that point, which is hardly fair to them.
The bright side is that we'd have all day hockey again in the first two rounds of the playoffs. That was a ton of fun last season, even if it was for all the wrong reasons.