Is it possible to still send BTC with multibit classic?

[GTTT]

I have some BTC that I mined back in 2014 on a Multibit Classic wallet.  I am trying to transfer everything to a Trezor and trying to figure out the safest and most cost effective way to do that.  I tired sweeping keys from Mulitbit into electrum.  I tried doing that yesterday and I swept 5 address with 86 transactions for a total of just over 12,700 bytes.  It said the fee was unknown. 

It does not say what the fee would be for sweeping into electrum.  The current version of multibit classic wallet I have I can set the highest transaction fee for .0005 BTC/kb or 50 satoshis/ byte.  If I set it to the highest fee, would the transaction go through or would it get stuck?   

Would I be screwed if it did not go through since Multibit classic is not supported?

[dotch]

I sent 2 BTC (also from 2014) from MultiBit Classic to Electrum over 3 months ago. One went trough within hours. The second one (a child of the first one) was stuck and remained unconfirmed.

After 3 days I managed to get it trough within 2 hours or so using the ViaBTC Transaction Accelerator. They do not have enough slots for everybody. The number of slots per hour are gone within a minute. The trick is to enter your Transaction ID within seconds after a new hour starts.

According to my knowledge moving BTC to a new client by simply sending them trough a regular transaction is even the best way to transfer them. Your BTC arrive in a wallet that has a seed. I haven't heard of any incomparability issues yet. If they really remain unconfirmed, they bounce back to you after a while. You won't loose them. I would recommend the highest fee possible in MultiBit Classic.

In Electrum 2.0, you cannot import private keys in a wallet that has a seed. You should sweep them instead. If you want to import private keys and not sweep them you need to create a special wallet that does not have a seed. For this, create a new wallet, select “restore”, and instead of typing your seed, type a list of private keys, or a list of addresses if you want to create a watching-only wallet.

Good luck!