I have an international move coming up but my book's just about ready to query. Knowing that it can take weeks for a response, my instinct is to send the first queries out when they're ready. But, do I mention that between certain dates I may not have internet access and thus would not be able to respond ASAP? How about if I'm not certain of the dates yet, the move being contingent on selling a house? I don't want to chance a bad impression by starting out with a delayed response. Would this be seen as presumptive? Insulting if the date is too far out? Or is it best not to mention it and just keep my devices as hooked up and charged as possible? Or wait til I'm settled before I query?
Don't query before you're in a position to reply in a timely manner.
That said, it seems foolish to wait to query when it's very likely true that there will be a lag time in replies.
I would suggest querying from a NEW email address that you set up just for queries, and ask someone to monitor it for you if/when you're out of wi-fi range.
That person can have a copy of the novel and send it as requested on your behalf. And if the agent asks something, your Designated Sender can reply that you're:
1. sailing the seven seas
2. digging out of prison
3. scouting locations in Canada for the horde of Americans contemplating a four-year sojourn there and will reply when you've resurfaced.
You probably don't want to saddle someone with your working email account (hell, I'd be leery of doing that to anyone even if I paid them a princely sum) but a dedicated email probably won't be too much trouble.
This way too, you're not sending things like "I'll be out of pocket for six weeks...I think" which is not something I want to see in a query letter.