My guess is that with roughly 2 months to recover, and about a month to train... you should be ok... I doubt that for those 2 months you will be completely off the bike... as long as you feel ok, and the doctor agrees... I'd go ahead, and at least ride the trainer... it's better than nothing... how may miles a day are you planning for your tour ?
as long as you keep some base going on... you should be good to go
Jeff